scholarly journals Topological Synthesis of Fractionated Geared Differential Mechanisms

1998 ◽  
Vol 122 (4) ◽  
pp. 472-478 ◽  
Author(s):  
Dar-Zen Chen ◽  
Kang-Li Yao

An efficient and systematic methodology for the topological synthesis of admissible fractionated geared differential mechanisms is presented. Based on the extension of the 2-dof automotive gear differential, it is shown that a fractionated geared differential mechanism can be decomposed into a main component and an input component. Characteristics of these two components are laid out, and the atlases of admissible input and main components are identified from the existing atlases of non-fractionated geared kinematic chains. With a systematic procedure to choose input and main components and select admissible connecting links, fractionated geared differential mechanisms with three and four input/output links are generated accordingly. [S1050-0472(00)00804-7]

Author(s):  
Dar-Zen Chen ◽  
Shuen-Chen Shieu

Abstract An efficient and systematic methodology for the topological synthesis of geared robotic mechanisms is developed. The approach is based on the idea that the kinematic structure of a geared robotic mechanism can be described by an equivalent open-loop chain (EOLC) and mechanical transmission lines (MTLs) which drive the joints of the EOLC. It is shown that an MTL can be decomposed as an input unit and several transmission units connected in series. The characteristics of the input and transmission units are laid out and a systematic methodology is developed to enumerate all admissible input and transmission units from the existing atlas of non-fractionated geared kinematic chains. The atlas of admissible MTLs are then generated accordingly. Thus, all admissible geared robotic mechanisms can be enumerated efficiently with the atlas of admissible MTLs and a preferred form of the EOLC. With this new methodology, some novel structures of geared robotic mechanisms are obtained and it is believed that new areas of application can be further explored.


1998 ◽  
Vol 120 (2) ◽  
pp. 230-239 ◽  
Author(s):  
Dar-Zen Chen ◽  
Shuen-Chen Shiue

An efficient and systematic methodology for the topological synthesis of geared robotic mechanisms is developed. The approach is based on the idea that the kinematic structure of a geared robotic mechanism can be described by an equivalent open-loop chain (EOLC) and mechanical transmission lines (MTLs) which drive the joints of the EOLC. It is shown that an MTL can be decomposed as an input unit and several transmission units connected in series. The characteristics of the input and transmission units are laid out and a systematic methodology is developed to enumerate all admissible input and transmission units from the existing atlas of nonfractionated geared kinematic chains. The atlas of admissible MTLs are then generated accordingly. Thus, all admissible geared robotic mechanisms can be enumerated efficiently with the atlas of admissible MTLs and a preferred form of the EOLC. With this new methodology, some novel structures of geared robotic mechanisms are obtained and it is believed that new areas of application can be further explored.


2018 ◽  
Vol 24 (2) ◽  
pp. 67-76
Author(s):  
Sujadi Sujadi ◽  
Hasrul Abdi Hasibuan ◽  
Meta Rivani ◽  
Abdul Razak Purba

Fresh fruit bunches (FFB) consist of fruit be composed grade in few spikelet. Fruit at a spikelet can be distinguished into performed fruit namely internal fruit, middle fruit and outer fruit as soon as each section contain parthenocarpy fruits. This research was conducted for determine composition and content fatty acid of oil at internal fruit, middle, outer and parthenocarpy fruit from oil palm fruit. Samples of fruit came from 3 – 5 spikelet the central of FFB. Result showed that oil content of outer fruit (46.9 + 9.9)% trend higher be compared middle fruit (42.8 + 10.3)% and internal fruit (39.1 + 9.5)%. Parthenocarpy fruits have a low oil content (14.2 + 16.2)% except yellowish fruit trend high relatively oil content. The main components of fatty acid at outer fruit, middle and internal are palmitic acid, oleic, linoleic and stearic with mean value respectively (44.8 – 45.8)%, (37.6 – 38.0)%, (9.9 – 10.9)% and (4.6 – 4.8)%. Oil content at parthenocarpy fruit have amount main component of fatty acid with performed fruit but composition of palmitic acid (40.0 + 5.9)% and oleic (34.6 + 8.4)% lower while linoleic acid (16.9 + 8.5)% and linolenic (1.6 + 1.8)% higher be compared to performed fruit. Simalungun variety has the highest oil content in the part of fruit, with that PPKS 540 and La Mé respectively. PPKS 540 variety has the highest oleic acid content while PPKS 718 has the highest linoleic content.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4393
Author(s):  
Cesar Auguste Badji ◽  
Jean Dorland ◽  
Lynda Kheloul ◽  
Dimitri Bréard ◽  
Pascal Richomme ◽  
...  

Essential oils of aromatic plants represent an alternative to classical pest control with synthetic chemicals. They are especially promising for the alternative control of stored product pest insects. Here, we tested behavioral and electrophysiological responses of the stored product pest Tribolium confusum, to the essential oil of a Brazilian indigenous plant, Varronia globosa, collected in the Caatinga ecosystem. We analyzed the essential oil by GC-MS, tested the effects of the entire oil and its major components on the behavior of individual beetles in a four-way olfactometer, and investigated responses to these stimuli in electroantennogram recordings (EAG). We could identify 25 constituents in the essential oil of V. globosa, with anethole, caryophyllene and spathulenole as main components. The oil and its main component anethole had repellent effects already at low doses, whereas caryophyllene had only a repellent effect at a high dose. In addition, the essential oil abolished the attractive effect of the T. confusum aggregation pheromone. EAG recordings revealed dose-dependent responses to the individual components and increasing responses to the blend and even more to the entire oil. Our study reveals the potential of anethole and the essential oil of V. globosa in the management of stored product pests.


DUST-BORNE TRACE GASES AND ODORANTS The analysis of dust-borne trace gases requires their i-solation from the dust particles. Procedures for the isolation and characterization of trace gases and odorants in the dust from pig houses are given by SCHAEFER et al. (29), HAMMOND et al.(30) and TRAVIS and ELLIOTT (31). Alcoholic solvents were found to be effective for the extraction of volatile fatty ac­ ids and phenols from the dust of hen (32) and pig houses (33), (34). Today, gas chromatography is usually used for the sepa­ ration and identification of the trace gases. Table IV gives a literature review of compounds identified in the dust of pig houses. There are only very few reports on investigations on the dust from hen houses (32). Most of the odours coming from livestock production units are associated with the biological degradation of the animal wastes (35), the feed and the body odour of the animals (1). Volatile fatty acids and phenolic compounds were found to con­ tribute mostly to the strong, typical odour of animal houses by the help of sensory evaluations parallel to the chemical analysis (29),(30). Table V gives quantitative values of volatile fatty acids and phenolic/indolic compounds found in the aerosol phase and in settled dust of piggeries, respectively. The results from the aerosol phase coincide, particularly as far as acetic acid is concerned. For the investigations of the settled dust the coefficients of variation (CV) and the relative values (%) characterizing the percentage of the single compounds as part of the total amount are quoted. The values are corrected with the dry matter content of the dust. Main components are acetic acid and p-cresol, respectively. Table VI compares results from air, dust and slurry in­ vestigations on VFA and phenolic/indolic compounds in piggeries. Relative values are used. When comparing the results derived from investigations on dust, air or slurry it is necessary to use relative values because of the different dimensions, for experience shows that in spite of large quantitative differ­ ences between two samples within the group of carboxylic acids and within the group of phenolic/indolic compounds the propor­ tions of the components remain rather stable (36). In the group of VFA acetic acid is the main component in air, dust, and slurry followed by propionic and butyric acid. The other three acids amount to less than 25%. In the group of phenols/ indoles p-cresol is the main component in the four cited in­ vestigations. However, it seems that straw bedding can reduce the p-cresol content; in this case phenol is the main compo­ nent , i nstead (37 ). 4. EMISSION OF DUST-BORNE VFA AND PHENOLS/INDOLES FROM PIGGERIES The investigations of dust from piggeries show that both VFA and phenols/indoles are present in a considerable amount. However, compared to the air-borne emissions calculated on the base of the results of LOGTENBERG and STORK (38) less than the tenth part (1/10) of phenols/indoles and about the hundredth part (1/100) of VFA are emitted by the dust, only. Table VII compares the dust-borne and air-borne emissions of VFA and


2018 ◽  
Vol 68 (1) ◽  
pp. 50-55
Author(s):  
V. P. Ostapovich

The author has studied the problem of the development of theoretical foundations and methodical tools for conducting job research within the National Police of Ukraine. The author has stated theoretical grounds of creating a profile for the profession of a detective; has revealed the possibilities of using some methods and means of job research for the development of modern profiles of the professions of the system of the National Police of Ukraine. It has been demonstrated that a profile of the profession as a set of parameters characterizing a successful specialist, a professional in a certain field of professional activity, is an important component of the job description. The main component of the profile is the characteristic of psychological peculiarities of professional activity.On the basis of experimental research, the author has formulated the requirements of the profession to the motivational sphere of a specialist, his abilities, temperamental and characterological traits, etc. The main components of the profile of a detective’s profession have been considered. The author has described such structural components of the profile of the profession as general characteristics of the activity, working conditions, negative factors, occupational risk factors, psychological characteristics and professionally important personal qualities of a specialist. The author has provided the demands of the profession to the sensory and perceptual sphere of a detective, general and special abilities, the features of temperament and character, motivation, emotional and volitional qualities. It has been emphasized that comprehensive study of professional police activity based on the development of profiles of the profession is a prerequisite for solving problems related to the efficiency of using personnel potential, optimizing the selection of the most appropriate candidates for the police force, training and retraining of personnel, rationalization of work and reduction of injuries, etc.On the basis of a broad experimental study, the author has established the list of the main professional qualities of a detective of the National Police; has determined the qualitative and quantitative psychological and psychophysiological indicators recommended for the professional activity. The author has also established psychological and psychophysiological contraindications for overtaking the professional activity of a detective (a criminal police officer).


2016 ◽  
Vol 24 (2) ◽  
pp. 67-76
Author(s):  
Sujadi Sujadi ◽  
Hasrul Abdi Hasibuan ◽  
Meta Rivani ◽  
Abdul Razak Purba

Fresh fruit bunches (FFB) consist of fruit be composed grade in few spikelet. Fruit at a spikelet can be distinguished into performed fruit namely internal fruit, middle fruit and outer fruit as soon as each section contain parthenocarpy fruits. This research was conducted for determine composition and content fatty acid of oil at internal fruit, middle, outer and parthenocarpy fruit from oil palm fruit. Samples of fruit came from 3 – 5 spikelet the central of FFB. Result showed that oil content of outer fruit (46.9 + 9.9)% trend higher be compared middle fruit (42.8 + 10.3)% and internal fruit (39.1 + 9.5)%. Parthenocarpy fruits have a low oil content (14.2 + 16.2)% except yellowish fruit trend high relatively oil content. The main components of fatty acid at outer fruit, middle and internal are palmitic acid, oleic, linoleic and stearic with mean value respectively (44.8 – 45.8)%, (37.6 – 38.0)%, (9.9 – 10.9)% and (4.6 – 4.8)%. Oil content at parthenocarpy fruit have amount main component of fatty acid with performed fruit but composition of palmitic acid (40.0 + 5.9)% and oleic (34.6 + 8.4)% lower while linoleic acid (16.9 + 8.5)% and linolenic (1.6 + 1.8)% higher be compared to performed fruit. Simalungun variety has the highest oil content in the part of fruit, with that PPKS 540 and La Mé respectively. PPKS 540 variety has the highest oleic acid content while PPKS 718 has the highest linoleic content.


Author(s):  
A. K. Dhingra ◽  
A. N. Almadi ◽  
D. Kohli

Abstract This paper presents closed-form polynomial solutions to the displacement analysis problem of planar 10-link mechanisms with 1 degree-of-freedom (DOF). Using the successive elimination procedure presented herein, the input-output (I/O) polynomials as well as the number of assembly configurations for five mechanisms resulting from two 10-link kinematic chains are presented. It is shown that the displacement analysis problems for all five mechanisms can be reduced to a univariate polynomial devoid of any extraneous roots. This univariate polynomial corresponds to the I/O polynomial of the mechanism. In addition, one of the examples also illustrates how trigonometric manipulations in conjunction with tangent half-angle substitutions can lead to non-trivial extraneous roots in the solution process. Theoretical conditions for identifying and eliminating these extraneous roots are also presented.


Author(s):  
Yufeng Luo ◽  
Tingli Yang ◽  
Ali Seireg

Abstract A systematic procedure is presented for the structure type synthesis of multiloop spatial kinematic chains with general variable constraints in this paper. The parameters and the structure types of the contracted graphs and the branch chains used to synthesize such kinematic chains are given for kinematic chains with up to four independent loops. The assignments for the constraints values of all the loops in a kinematic chain are discussed. Using these as the basis, the structure types of the multiloop spatial kinematic chains with hybrid constraints could be synthesized.


2001 ◽  
Vol 56 (7-8) ◽  
pp. 597-602 ◽  
Author(s):  
Maria Tsoukatou ◽  
Lanna Cheng ◽  
Constantinos Vagias ◽  
Vassilios Roussis

Halobates is the only insect genus with representatives in the open ocean. How adults find one another at sea has long been an intriguing issue. Since chemical communications have been demonstrated in a related marine veliid Trochopus, and laboratory bioassays indicated behavioral differences between males and females when insect extracts were presented, we carried out similar studies on Halobates. Analyses of surface lipid constituents of female and male Halobates hawaiiensis revealed marked differences. Palmitic and oleic acid, major constituents in the male extracts, were absent in the female extract, whereas nonacosenol, dominating the female extracts, was not detected in the male extracts. Analyses of nymphal extracts indicated an intermediate chemical profile. Surface waxes of all insect stages investigated showed nonacosanol and isononacosanol to be main components. “Headspace” analyses of airborne chemicals showed high levels of 4-hydroxy-4-methyl-2-pentanone and benzal­dehyde from the male, whereas benzyl alcohol was the main component in the female mixture


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