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Ash gourd (syn:wax gourd, winter melon, white gourd, white pumpkin, ash pumpkin, Chinese preserving melon and hairy melon) is a vegetable belonging to family Cucurbitaceae and genus Benincasa with only one cultivated species, Benincasa hispida (Thunb.) Cogn. (2n=2x=24). Ash gourd is an important vegetable especially in the Indo-China region, which is also the major producer of ash gourd (Rubatzky and Yamaguchi, 1997), but it is also a potential crop of tropical Africa and America (Sirohiet al., 2005).

Borer pests cause significant yield losses and are one of the most serious production constraints in tropical vegetable production. For instance, eggplant fruit and shoot borer (EFSB), Leucinodes orbonalis Guenée (Lepidoptera: Pyralidae) reduces yield as much as 70% (Dhandapani et al., 2003). Tomato fruit borer, Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) causes about 5 to 55% loss in almost all the tomato producing areas in the world (Kashyap and Batra, 1987). Up to 80% yield losses have been reported in various vegetable and grain legumes due to legume pod borer (LPB), Maruca vitrata F. (Lepidoptera: Pyralidae) damage (Singh et al., 1990; Sharma, 1998; Gressel et al., 2004; Hammig et al., 2008; Zahid et al., 2008). Due to higher yield losses, growers tend to apply extremely high quantities of chemical pesticides to control borer pests on vegetable crops. Because the borer larvae are exposed on external plant parts only for a brief time after hatching, the window for effective pesticide application is very brief; vegetable farmers spray throughout the growing season, but without satisfactory results. A survey of pesticide use in Bangladesh indicated that farmers spray up to 180 times with chemical insecticides during a year to protect their eggplant crop against EFSB (SUSVEGAsia, 2007). Pesticide application often exceeded 50 sprays per tomato crop season in south India (Nagaraju et al., 2002). In Bangladesh, country bean (Lablab purpureus) is being sprayed at weekly or biweekly intervals—sometimes every day—to control LPB (Hoque et al., 2001). On average, farmers used 10-24 kg/ha of pesticides in cabbage and cauliflower in India to manage the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) and other pests (Weinberger and Srinivasan, 2009).

Horticulture includes fruits, vegetables, floriculture, spices, tubers, plantation crops, medicinal and aromatic plants and mushrooms. The sector has established its importance in improving land use, promoting crop diversification, generating employment and above all providing nutritional security to the people. Even though India is the second largest producer of horticulture produces in the world, our per capita consumption of fruits and vegetables are very low.

“Age and Area”: The hypothesis (by Willis) that the older a species is, the wider will be its geographical distribution.

A-Without; lacking.

A.I.: See active ingredient.

A.O.U. Code: A code of nomenclature published in 1885 (revised 1908) by the American Ornithologists’ Union for the standardization of bird nomenclature.

Ab-Away from; off.

Bacillus thuringiensis (Bt): Soil-inhabiting bacterium that produces an insecticide effective against larval stages of many species of Lepidoptera, although some strains are effective against various beetle, mosquito, and blackfly larvae.

Backcross: A cross between a hybrid and one of its parents; a cross between a heterozygote and a homozygote (cf. Hybridization, Heterozygous, Homozygous).

Bacterial insecticide: Bacteria pathogenic to insects (e.g., Bt or B. popilliae). Applied using application techniques also used for chemical pesticides.

Bacterium (pl. bacteria): Microscopic, prokaryotic, single-celled organisms having cell walls but lacking membrane-bound organelles. Important in decomposition, nitrogen fixation and other symbiosis, and as pathogens. A significant component of soil food webs.

Bait (B): A pesticide formulation that combines an edible or attractive substance with a small amount of toxic active ingredient (usually about 5%). Baits containing poisonous chemical and food stuffs are primarily offered to pests as food for control of animal pests like mollusks, cutworms, and rodents.

Caecae: Saclike or tubular structures open at only one end (blind), often opening from the mid-intestine (Fig. 41).

Caecum (pl. caeca): A blind-ending tube or sac or pouch sac of the alimentary canal (L. caecus= blind) e.g., haepatic caecae in the alimentary canal of insects (Fig. 41).

Calamistrum: One or two rows of curved spines on the metatarsus of the hind legs (spiders; fig. 608, clm).

Calibration: The adujustment of application equipment so that a defined quantity of chemical or other material is applied per unit time or area.

Calling: A vergin female moth releasing sex pheromones to attract males for the purpose of mating.

Calliphorin: A protein produced in the fat body and stored in the haemolymph of larval Calliphoridae (Diptera).

Dall code: A code of nomenclature prepared by W.H. Dall at the direction of the American Association for the Advancement of Science (1877).

Damage boundary: The level of injury where damage can be measured.

Damage threshold: Pest population above which crop loss occurs.

Damage: Measurable reduction in crop growth or yield; or a measurable loss of host utility, most often including yield quantity, quality, or aesthetic appeal.

Damping off: Infection of newly formed roots and stems of young seedlings by fungi or bacteria, typically at soil level, resulting in decay or seedling death.

Danger: A signal word used on pesticide labels to inform the user that the pesticide is highly toxic, as defined by FIFRA. The word poison and the skull and crossbones symbol always accompany the signal word danger.

Early postemergence: The application of herbicide after plant emergence and during the initial growth phases of crop or weed seedlings.

EC: See emulsifiable concertrate.

Ecdysial cleavage lines: Preformed lines of weakness along which the shed cuticle of the cranium splits during ecdysis; cuticle in the region of these lines lacks the exocuticle (Fig. 100).

F₁ generation: The first-generation offspring of a particular mating.

F₂ generation: Derived from a mating within the F₁ generation.

Face: The front of the head, below the frontal suture (Fig. 108).

Facet: The hexagonal external surface of an individual compound eye unit of ommatidium.

Facies: In taxonomy, the general aspect, appearance, or habits of a species or group.

Gain threshold: The beginning point of economic damage, expressed in amount of harvestable produce; when cost of suppressing insect injury equals money to be gained from avoiding the damage.

Galea: The lateral lobe of the maxillary stipes; tonguelike, distal lobe attached to the stipes of the maxilla; an apical lobe of the maxilla of an insect; the outer two-jointed lobe of the “pincers” present on the maxilla of insect mouthparts; in adult Lepidoptera the two are joined and enlarged to form the proboscis. (Fig. 63)

Gall: Swellings, deformities, or growths of plant tissue that result from the activities various types of pests, including bacteria, nematodes, mites and insects; an abnormal growth of plant tissues, caused by the stimulus of an animal or another plant (Fig. 128).

Gallicolous: Living in a plant gall either as the producer or inquiline.

Hard pesticide: One which persists for a long time in the environment; particularly applies to organochlorine insecticides.

Habit, Habitus: The general appearance of an organism; facies.

Habitat modification: Alteration of the environment where an organism occurs, e.g., cultivating land for agriculture.

Habitat: The environmental conditions and associated organisms that occur in a particular site; the place where plants and animals live, usually with a distinctive boundary (e.g. field, pond, sand-dune, rocky crevice); the natural or usual dwelling place of an individual or group of organisms. (L. habitus = condition).

Habituation: A form of associative learning in which a given stimulus no longer elicits a response; learning not to respond to a stimulus that provides no reward or punishment.

Habituation: Reduction in the response to a stimulus with repeated exposure, through modification of the central nervous system.

Haematophagous: Blood-sucking; blood –feeding.

Haemocoel (also hemocoel): The main body cavity of many invertebrates, including insects, formed from an expanded ‘blood’ system that is filled with blood (haemolymph) within which the internal organs lie.

Ichthyology: Science dealing with the study of fishes – a class of aquatic vertebrates most of whom depend for respiration exclusively on oxygen dissolved in water (Gr. ichtys = fish + logos = study).

Idiobiont: A parasitoid that prevents its host from developing any further, by paralysis or death; see also Konobiont.

IGR: See insect growth regulator

Ileum: The second section of the hindgut, preceding the colon differentiated region of the anterior intestine of the hindgut preceding the rectum in some insects (Fig. 120).

Imaginal buds: See imaginal disc.

Jet: Liquid emitted from a nozzle orifice (in USA = nozzle).

JH: An abbreviation of juvenile hormone.

Johnston’s organ: A sense organ similar to a chordotonal organ, located in the second antennal segment of most insects; functions in sound reception in some Diptera (Fig. 153); an organ in the pedicel of the antenna, consisting of a cluster of chordotonal sensilla.

Kairomone: A chemical produced by an individual of one species that has a beneficial effect on the recipient individual of another species; a chemical that is adaptively favourable to the receiving organism; an interspecific messenger substance that benefits the receiver but not the releaser (e.g., attractants, excitants); an interspecific chemical messenger that benefits the receiver but not the emitter; a communication chemical that benefits the receiver and is disadvantageous to the producer; see also Allomone; Synomone.

Karyological character: A character involving chromosome structure or number (cf. Taxonomic character).

Keeled: With an elevated ridge or carnia.

Keratin: The inert exoskeleton protein of vertebrate animals forming skin, hair, feathers, claws, nails, scales, etc.; similar in structure and function to the arthropod chitin.

Keratolytic: Pertaining to or promoting loosening or separation of the outer layer of the skin.

Label: Technical information about a registered pesticide in the form of printed material attached to, or printed on, the pesticide container. It is illegal to use the pesticide in ways inconsistent with the label.

Labella (sing. labellum): In certain flies, paired lobes at the apex of the proboscis, derived from labial palps; apical spongelike structure on the proboscis of nonbiting muscoid flies (Fig. 156).

Macro: Large.

Macro-and microconsumers: In an ecosystem the primary consumers, feed on plants while other consumers, e.g., secondary and tertiary consumers are called macroconsumers. The decomposers, like bacteria and fungi, are called microconsumers.

Macro-and micronutrients: Some salts or elements needed in relatively large amount are termed macronutrients while some others though essential for maintaining the life-system are required in minute amounts and are the micronutrients.

Macroclimate: General climate prevailing over a large area, considered as a unit. The opposite is microclimate.

Macroevolution: Major phylogenetic patterns that develop over wide spans of geological time.

Macrofauna: The larger members of a particular fauna. Open to different levels of interpretation for they may be larger vertebrates or alternatively the larger insects of a habitat. The opposite is microfauna.

Macrogamete: The female gametocyte of a malaria parasite, Plasmodium spp; see also Microgamete.

Macrophage: An eater of large particles; see also Microphage.

Naiad: The immature stage in insects with incomplete metamorphosis that feed and develop in water; an aquatic, gill-breathing, immature instar of hemimetabolous insect.

Narcotic: A chemical that causes reversible depression of the nervous system.

Narrow spectrum (as applied to insecticides): Having an effect on only a narrow range of insects.

Nasus: A nose, the snout of certain termite soldiers (nasutes).

Nasute (pl. nasuti): A type of soldier caste in certain termites; this form bears a median frontal rostrum or snout through which it ejects a defensive fluid; the jaws are small or vestigial.

Nasutus (pl., nasuti): An individual of a termite caste in which the head narrows anteriorly into a snoutlike projection.

Natality: Population ‘increase’ factor; birth rate; often measured as total number of eggs or eggs per female per unit of time.

Objective synonym: An absolute or nomenclatural synonym resulting from the proposal either of a replacement name for a supposedly preoccupied name or of names based on the same specimen, illustration, or taxonomic entity (cf. Synonym, Subjective synonym).

Obligate parasite: A parasite that requires a living host to survive and reproduce and which cannot exist in any other way.

Obligatory: Compulsory, or exclusive; e.g. obligatory diapause is a resting stage that occurs in every individual of each individual of each generation of a univoltine insect.

Oblique sternals: Lateral abdominal muscles in other than longitudinal or dorsal-ventral orientation

Pacemaker: A region from which waves of contraction in the heartbeat cycle are propagated.

Paedogenesis: Reproduction by the juvenile form; the production of eggs or young by an immature or larval stage of an animal; reproduction by larviform individuals.

Paeudotrachea: A ridged groove on the ventral surface of the labellum of some higher Diptera, used to take up liquid food.

Page precedence: The principle that when two or more conflicting homonyms or synonyms are published in the same work (or portion of a work) and, as a consequence, are of the same date, the names shall have priority according to the sequence in which they first appear in the work (or portion) concerned.

Paint gun: Type of small, hand-carried, air-blast machine.

Pair-wise coevolution: see Specific coevolution.

Quadrangle: A cell immediately beyond the arculus (Odonata, Zygoptera).

Quadrat: A four-sided defined area from which a sample is collected, used in population determination.

Quadrivoltine: Four life cycles per year.

Qualitative defenses of plants: Toxins and small-molecular-weight compounds (such as alkaloids) that are active against the physiological systems of phytophagous insects; complex, digestibility-reducing substances (such as tannins) that reduce the ability of insects to feed on plants.

Quantitative specificity: In serology, the principle that a given kind of antibody will react more strongly, under comparable conditions, with the particular kind of antigen used in its formation than with any other substance (cf. Antibody, Antigen, and Precipitin reaction).

Race: A subspecific category that is based on particular attributes, such as behavioral or physiological (other than morphological) differences; similar to a subspecies; often used in describing plant pathogens.

Race: Subspecies (q.v.).

Race: A naturally occurring group within a species usually visually indistinguishable but with some physiological difference from other members of the species, e.g., with a different plant host range. cf. strain.

Radial cell: A cell bordered anteriorly by a branch of the radius; the marginal cell (Hymenoptera).

Radial cross vein: A cross vein connecting R₁ and the branch of the radius immediately behind it.

Radial sector: The posterior of the two main branches of the radius.

Radiation: See Adaptive radiation.

Sabadilla: A botanical insecticide extracted from seeds of Schoenocaulon officinale

Safener: A chemical additive that reduces the phytotoxic properties of a pesticide.

Salivarium or salivary reservoir: The cavity into which the salivary gland opens, between the hypopharynx and the labium.

Salivary gland: The exocrine gland that produces saliva and typically associated with the labial segment; highly variable in size, structure, and function.

Saltation: Discontinuous variation produced at a single step by mutation (cf. Mutation).

Tactile: Referring to the sense of touch.

Taenidium (pl. taenidia): The spiral thickening of the tracheal wall that prevents collapse; helical fold in the cuticular lining of tracheae and tracheoles (Fig. 230); cuticular ridges that support the walls of tracheae; a spiral or circular thickening of the inner surface of the tracheae.

Ultra low volume spraying (ULV): The application of pesticides in extremely concentrated or undiluted form using 10 liters or less per hectare (1 gal per acre); highly concentrated pesticide applied without dilution at a rate of 0.5 gallons per acre or less.

Umbilical cord: The cord containing blood vessels supported by connective tissue that unites the embryo or fetus of a mammal with the mother during development in the uterus. (L. umbilicus = navel).

Ungulate: Having hoofs, as a deer or (L. ungula = hoof).

Unguligrade: Walking or adopted for walking on hoofs. (L. ungula = hoof + gradior = to step).

Ungue: Pretarsal claw.

Unguiculate: Having claws, as a cat. (L. unguis = claw).

Vagina: A pouch-like or tubular genital chamber of the female genitalia; external opening of the female reproductive system; or the terminus of the female reproductive tract that opens to the outside; or the terminal portion of the female reproductive tract which receives the copulatory organ of a male in mating (L. sheath).

Valid name: The name of a taxonomic category which is available nomenclaturally and also is recognized as valid on Zoological grounds (cf. Available name).

Valvar lamina: The posterior margin (usually prolonged posteriorly) of the eighth abdominal sternite (female Odonata).

Valve: In animals, any structure that limits or closes an opening; the thin folds in veins, lymph vessels, or hearts or the circular muscles about a tubular exit; also, either external shell of bivalve mollusk, brachiopod, or some crustaceans.

Valvifer (s): A basal sclerite of a valve of the ovipositor, articulating with the tergum; or proximal structures of the ovipositor that bear the valvulae; in female insect genitalia, derivations of gonocoxites 8 and 9, supporting the valves of the ovipositor.

Valvulae: Distal structures of the ovipositor borne on the valvifers; the three pairs of processes forming the sheath and piercing structures of the ovipositor.

Wettable powder (WP): An insecticide formulation consisting of finely ground solid particles of active ingredient plus inert carrier; forms a suspension when added to water.

Waggle dance: A communication dance of honey bees. A form of recruitment in the honey bee in which direction and distance to a food source are indicated.

Waiting period: See time interval.

Waiting period: The prescribed period between last application of a pesticide to crop and harvest.

Warble: The swelling on the host body caused by the larva of a warble fly.

Warm-blooded (Homoiothermous): Animals in which body temperature normally does not change with changes in atmospheric temperature e.g.birds and mammals.

Warning: Signal word used to designate a moderately toxic pesticide; oral LD₅₀ = 50 to 500 mg/kg body formulated.

Xerophyte: Plant adapted for survival in desert or physiologically dry soil.

Xylem: The water-conducting woody tissue in vascular plants.

Xylomycetophagy: Cultivation and feeding upon symbiotic fungi growing in woody tree tissues; for example, some Scolytidae.

Xylophage (adj. xylophagous): An eater of wood.

Xylophagy: Feeding on xylem tissues.

Yellow fever: An infectious, mosquito-transmitted viral disease.

Abnormal combustion: Combustion that does not proceed in the normal way, in which knock, pre-ignition, run-on or surface ignition occurs. Refer knock.

Abrasion: It is the surface discontinuity brought to any solid by the process of removal of surface material through friction of another solid, liquid or gas or combined thereof.

Absolute or specific humidity: It is the mass of water vapour present in a unit mass of dry air. It is also called as humidity ratio.

Absolute instrument: It is an instrument, which measures a quantity (such as pressure, temperature etc.) in absolute units by means of simple physical measurements on the instrument.

Absolute pressure: It is the actual pressure at a given position and it is measured relative to absolute vacuum (i.e., absolute zero pressure). Absolute pressure = pressure shown on the pressure gauge + atmospheric pressure. At sea level, atmospheric pressure is 14.7 psi (1.033kg/cm²).

Babbitt: 1. A tin base alloy containing 88% tin, 8% antimony and 4% copper. 2. In machinery, to line, bush, fill or face with Babbitt metal, e.g. to babbit a bearing.

Back furrow: A raised ridge left at the centre of the strip of land when ploughing is started from centre to side. See Fig. 1B.

Backfire: The accidental explosion of an overly rich mixture in the exhaust manifold of a spark-ignition engine. Backfire conditions can also develop if the premature ignition occurs near the fuel intake valve and the resultant flame travels back into the induction system.

Backlash: The clearance or play between two parts, such as meshed gears.

Cable conveyor: A power conveyor in which a trolley runs on a flexible, torque transmitting cable that has helical threads.

Cable: 1. A general term applied to rope or chain used for engineering purposes. 2. The standard wire with insulating cover used for conducting electrical current.

Cage harrow: A rolling harrow with horizontal shafts each fitted with star shaped tines joined by rods forming the lines of cylinder.

Dah: A metal with handle used for cutting trees and cleaning jungle growth. See Fig.1D.

Dead axle (tractor trolley): An axle beam, which does not drive the road wheels. Usually refers to a rear axle which does not have any rotating parts within it, but on which the rear wheels are mounted with antifriction bearing.

Dead centre: 1. The centre, which is fitted into the tailstock of a lathe and does not rotate with the work. 2. The extreme top or bottom position of the crankshaft throw at which the piston is not moving in either direction.

Dead furrow: An open trench left in between two adjacent strips of land after finishing the ploughing operation. See Fig.1B

Dead weight: The weight of a vehicle or carrier itself as distinguished from carried or live load.

Ear plug: A device made of a pliable substance, which fits into the ear opening; used to protect an ear from excessive noise or from water.

Ear protector: A device, such as a plug or ear muff, used to protect the human ear from loud noise that may be injurious to hearing, such as that of jet engines.

Earned value: The budgeted cost of the work performed for a given project.

Earth moving: Tillage action and transport operations utilized to loosen, load, carry and unload the soil.

Earthmover: A machine used to excavate, transport, or push earth.

Fabrication: The act of building or putting together. Forming into a whole by uniting or assembling of parts.

Face lathe: A short-bed, deep gap lathe designed for the machining of large, flat surfaces.

Face milling: Milling flat surfaces perpendicular to the rotational axis of the cutting tool.

Faceplate or face chuck: A circular plate for attachment to the spindle in the headstock of a lathe. Work may be clamped or bolted to it. The slots engage the tail of the lathe dog.

Factor of safety: The number, which results by dividing the ultimate strength of a material by the actual stress on a sectional area.

Factor of stress intensity: The ratio of the maximum stress to which a structural member can be subjected to the maximum stress of safety.

Gadget: A slang word applied to any small, handy appliances or devices.

Gagging tape: A metal measuring tape used to determine the depth of liquid in a tank.

Gal.: The unit of acceleration in the centimeter-gram-second system, equal to 1 centimeter per second square; commonly used in geodetic measurement. Formerly known as Galileo, symbolized as Gal.

Galling: A characteristic of metals, which causes them to seize when, brought into intimate contact with each other. A material, which is subjected to galling, is one, which will seize or ‘freeze’ when brought into close contact with like material under pressure and no lubricant.

Gallows plough: An animal-drawn plough, the end of the beam rests freely on a bolster fixed to two front wheels, which is drawn through the front wheel assembly.

Galvanic corrosion: The accelerated corrosion of one metal when it is connected with a more noble metal, e.g. if steel and copper are connected together in seawater, the steel will suffer accelerated corrosion and the copper will be protected.

Half round file: A file, which is flat on one side and curved on the other. The amount of convexity never equals a semicircle.

Half section: In mechanical drawing, a sectional view that terminates at the centreline, showing an external view on one side of the centerline and on the other side an interior view.

Hammer: An instrument or tool used for striking blows in metalworking, driving nails, etc. Hammers are of various kinds, each bearing a name according to the purpose it has to serve.

Hammer mill: 1. A type of impact mill or crusher in which materials are reduced in size by hammers revolving rapidly in a vertical plane within a steel casing. Also known as beater mill. 2. A grinding machine, which pulverizes feed and other products by several rows of thin, hammers revolving at high speed.

I beam: A steel beam shaped like the letter I, used in structural work.

I. H.P. (Indicated Horse Power): ‘Pure’ horse power as measured in the combustion chamber before friction and other loses are subtracted.

IC Engine (ICE): Internal Combustion Engine.

Ideal compression-compression refrigeration cycle: completely vaporizes the refrigerant before it is compressed and expands the refrigerant with a throttling device, such as an expansion valve or capillary tube. The compression-compression refrigeration cycle is the most widely used cycle for refrigerators, air-conditioning systems, and heat pumps. It consists of four processes:l- 2 Isentropic compression in a compressor; 2-3 Constant- pressure heat rejection in a condenser; 3-4 Throttling in an expansion device; 4-1 Constant-pressure heat absorption in an evaporator

Ideal cycle: is an actual cycle stripped of all the internal irreversibilities and complexities. The ideal cycle resembles the actual cycle closely but is made up totally of internally reversible processes.

Ideal gas: Is a gas that obeys the ideal-gas equation of state.

Jack, electric: A form of metallic spring contact, connection being made by inserting a plug, which is attached to a cord. Commonly used on telephone switchboards and radios.

Jack, hydraulic: Device for raising weight or exerting pressure by pumping oil or other liquid under a piston or ram.

Jack: A mechanical device used for lifting heavy loads through short distances with a minimum expenditure of manual power.

Jacket: An outer casing, as around a boiler or tank, to preserve heat or cold, or around a motor cylinder, permitting a flow of water to prevent overheating.

Jacking up: The raising up of masses of machinery and heavy structures by means of jacks.

Jackscrew: Small screw jacks for leveling work in jigs.

Kelvin scale: The thermodynamic temperature scale in the SI and is named after Lord Kelvin (1824-1907). The temperature unit on this scale is the Kelvin, which is designated by K (not °K; the degree symbol was officially dropped from Kelvin in 1967). The lowest temperature on the Kelvin scale is 0 K.

Kelvin unit: magnitude was established at the International Conference on Weights and Measures in 1954. The triple point of water (the state at which all three phases of water exist in equilibrium) was assigned the value 273.16°K (0.01 °C). The magnitude of a Kelvin is defined as 1/273.16 of the temperature interval between absolute zero and the triple-point temperature of water. The magnitudes of temperature units on the Kelvin and Celsius scales are identical (1 K, 1°C). The temperatures on these two scales differ by a constant 273.16.

Labeled: Equipment or materials to which has been attached a label, symbol or other identifying mark of an organization acceptable to the “authority having jurisdiction” and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

Laboratory: A place where scientific tests, experiments, analysis, etc., are carried on.

Ladder: An aid to climbing. Usually made of two parallel uprights connected by regularly spaced rungs.

Ladle: Receptacle used for taking the molten metal from the cupola, in transporting it, and in pouring it into the molds. Ladles are of various shapes and sizes with capacities from 25 pounds to 100 tons.

M

Mach number: Named after the Austrian physicist Ernst Mach (1838-1916), is the ratio of the actual velocity of the fluid (or an object in still air) to the velocity of sound in the same fluid at the same state.

Machine: 1. A combination of rigid or resistant bodies having definite motions and capable of performing useful work. 2. A device for transforming or transferring energy.

Machine drawing: A mechanical drawing of a machine or machine parts provided with notes and dimensions for workshop information.

Machine drilling: The d rillin g of work under a power-driven machine.

Machine molding: The use of special machines in the preparation of molds for the production of castings.

Machine rating: The amount of power a machine can deliver without overheating.

Machineable: Material capable of being finished by tools or cutters in or on a machine tool.

Machinery: A group of machines; also, the working parts of an engine or machine.

Machining: Performing various cutting or grinding operations on a piece of work.

Natural gas: Produced from gas wells or oil wells rich in natural gas. It is composed mainly of methane, but it also contains small amounts of ethane, propane, hydrogen, helium, carbon dioxide, nitrogen, hydrogen sulphate, and water vapour. It is stored either in the gas phase at pressures of 150 to 250 atm as CNG (compressed natural gas) or in the liquid phase at 162° C as LNG (liquefied natural gas).

Natural-draft cooling tower: Uses the naturally occurring density gradients between the inside air-water vapour mixture and the outside air which create an airflow from the bottom to the top of a wet cooling tower.

Needle valve: A valve in which the flow of liquid or gas is regulated by the adjustment of a pin or needlepoint, which sets in a cone-shaped depression having a small hole at the bottom.

Negative: One of the two terminals in an electrical circuit, presumably the one through which the current returns to the source.

Negative camber: The condition existing when two tyres are closer together at the top than at the bottom.

Oak: A hard, durable, and very strong wood used for many purposes like furniture, flooring, decoration etc.

Octane number: It is the percetage of iso-octane (C₈H₁₈) in the mixture of iso-octane and normal heptane (C₇H₁₆), when it produces the same knocking effect as the fuel under test. It is used to indicate the octane rating of a gasoline, describes the anti-knock properties of a fuel when used in an internal combustion engine. Knock is a secondary detonation that occurs after fuel ignition due to heat buildup in some other part of the combustion chamber. When the local temperature exceeds the auto ignition temperature, knock occurs.

Octane rating: A measure of the antiknock properties or engine knock resistance of a gasoline. The higher the octane rating, the more resistant the gasoline is to abnormal combustion.

Octane requirement: The fuel octane number needed for efficient operation (without knocking or spark retardation) of an internal combustion engine.

Odorization: A process of adding a distinctive odor to natural gas so that its presence can be easily detected.

Packing: 1. The material, which is enclosed in a stuffing box for the purpose of preventing leakage around a piston rod. 2. The act or process of inserting packing material. 3. Blocking up.

Paddy dehusker: An equipment to remove husk from paddy grain. It is also known as paddy Sheller.

Paddy separator: A machine, which is used for the separation of brown rice from the paddy brown rice mixture.

Paddy thresher, pedal operated: Equipment used for threshing of paddy crop, consisting of mainly a balanced cylinder with series of threshing teeth fixed on slats and worked by a pedal and gear drive mechanism.

Quadrangle: A square or quadrangular space surrounded by buildings, as on college grounds.

Quadrant: 1. The quarter of a circle, an arc of 90°. 2. An instrument for measuring altitudes.

Quadrilateral: A plane figure with four sides and four angles.

Quarter turn belt: The arrangement of a belt to drive two shafts, which are at right angle.

Quarter turn drive: A belt drive connecting pulleys whose axes are at right angles.

Quartering machine: A machine that bores parallel holes simultaneously in such a way that the centre lines of adjacent holes are at 90 deg. apart (axes of the holes are perpendicular to the plane on which an angular measurement are taken.)

R

Rabbet: A rectangular groove or cut made in the edge of a board, so that another similar cut may fit into it to form a rabbet joint.

Rack and pinion: A gear arrangement consisting of a toothed bar that meshes with a pinion. These are used to transform circular motion in to rectilinear motion and vice versa.

Rack and pinion steering: A steering system in which the rotation of pinion gear at the end of the steering column moves a toothed bar (the rack) left or right to transmit steering movements.

Radial arm: The movable cantilever, which supports the drilling saddle in a radial drilling machine.

Radial bearing: Bearing made with cylindrical or with barrel shaped rollers. The direction of action of the load transmitted to the axis of shaft.

Radial drill: l.A drilling machine in which the drill spindle can be moved along a horizontal arm, which itself can be rotated about a vertical pillar. 2. A heavy drilling machine, so constructed that the position of the drill can be adjusted to the work without moving the latter.

Radial engine: An engine, which has stationary cylinders, arranged radially around a common crankshaft.

SAE: Society of Automotive Engineers; used to indicate a grade or weight of oil measured according to the SAE.

Safe load: The load that a piece can support without exceeding the working unit stress.

Safety device: An installation designed to protect the operator or other persons. E.g., shields, grass-catching equipment, deflectors, covers for chains, belts, drive shafts, etc.

Safety factor: The degree of surplus strength over and above normal requirements, which serves as insurance against failure.

Safety hitch: A hitch incorporating a device to avoid breakage when an implement works against an abnormal resistance.

Safety valve: 1. An automatic valve, which opens and relieves the pressure when it reaches a predetermined value, thereby protecting the system and operator. 2. A safety device for allowing steam or water to escape from a boiler when the pressure may become dangerous. Usually adjusted to permit not more than 5 pounds of pressure above maximum allowable working pressure of the boiler.

T bolt: A bolt shaped like the letter “T, the head being a transverse piece, which fits into the recessed under cut T slots, as on a table of a milling machine or planning machine.

T head engine: A cross section of an engine block resembles the letter T. Valves are arranged on both sides of the engine; requiring two camshafts and two camshafts drive gears. An expensive type of construction.

Tachometer: An instrument for measuring the speeds of shafts in revolutions per minute.

Tail pulley: A pulley at the tail of the belt conveyor opposite the normal discharge end; may be drive pulley or an idler pulley.

Tail screw: The screw, which operates the spindle of the tailstock on a lathe.

Taillight: A signal light, required by law to be carried on the rear of every automobile, and lighted when the car is driven at night.

Tailstock: The movable head of a lathe as distinguished from the headstock, which is fixed.

Take up: A tensioning device in a belt conveyor system for taking up slack of loose parts.

U clamp: A clamp shaped like the letter ‘U’ used for clamping down work on planer beds.

Ultimate strength: The highest unit stress that can be sustained, this occurring just at or just before rupture in stress strain diagram.

Ultrasonic drilling: A vibration drilling method in which ultrasonic vibrations are generated by the compression and extension of a core of electrostatic or magneto static material in a rapidly alternating electric or magnetic field.

Ultrasonic machining: The removal of material by abrasive bombardment and crushing in which a flat-ended tool of soft alloy steel is made to vibrate at a frequency of about 20,000 Hz and an amplitude of 0.001-0.003 inch (0.0254-0.0762 millimeter) while a fine abrasive of silicon carbide, aluminum oxide, or boron carbide is carried by a liquid between tool and work.

Uniform: Implies no change with location over a specified region.

V belt: An endless power transmission belt with a trapezoidal cross section, which runs in a pulley with a V-shaped groove. The top surface of the belt approximately flush with to top of pulley. V belt transmits higher torque at less width and tension than a flat belt.

V blocks: Metal blocks cut ‘V’ shaped on one side to permit holding cylindrical work while machining or testing.

V type engine: An engine with cylinder blocks arranged in a ‘V’ shape. One crankshaft serves both banks of cylinders.

Vacuum: Negative gauge pressure, or a pressure less than atmospheric pressure. Vacuum can be measured in psi, but is usually measured in inches or millimeters of mercury (Hg); a reading of 30 in. Hg (762 mm Hg) would indicate a perfect vacuum.

Walking machine: A machine designed to carry its operator over various types of terrain; the operator sits on a platform carried on four mechanical legs, and movement of his arms control the front leg of the machine while movement of his legs control the rear legs of the machine.

Wane: Wane is a defect in a timber or plank.

Washer: A small, flat, perforated disk, used to secure the tightness of a joint, screw, etc.

Washer cutter: A device having a fixed center and either one or two adjustable cutting points for cutting washers from leather, rubber, etc.

Waste heat: Energy, that must be dissipated to the atmosphere from a process such as the heat transferred from condensing steam in the condenser of a steam power plant.

Waste spark system: An ignition system, that energizes the spark each time the piston is at top dead center whether or not the piston is on the compression stroke or on its exhaust stroke. For hydrogen engines, the waste sparks are a source of pre-ignition.

Water (H₂O): 1. A colorless, transparent, odorless, tasteless liquid byproduct of the combining of hydrogen and oxygen, 2. The liquid form of steam and ice. Fresh water at atmospheric pressure is used as a standard for describing the relative density of liquids, the standard for liquid capacity, and the standard for fluid flow. 3. The melting and boiling points of water are the basis for the Celsius temperature system. 4. Water is the only substance that expands on freezing as well as by heating, and has a maximum density at 4°C.