Polarizers, optical bridges and Sagnac interferometers for nanoradian polarization rotation measurements

The ability to measure nanoradian polarization rotations, $\theta_F$, in the photon shot noise limit is investigated for partially crossed polarizers (PCP), a static Sagnac interferometer and an optical bridge, each of which can in principal be used in this limit with near equivalent figures-of-merit (FOM). In practice a bridge to PCP/Sagnac source noise rejection ratio of $1/4\theta_F^2$ enables the bridge to operate in the photon shot noise limit even at high light intensities. The superior performance of the bridge is illustrated via the measurement of a 3 nrad rotation arising from an axial magnetic field of 0.9 nT applied to a terbium gallium garnet. While the Sagnac is functionally equivalent to the PCP in terms of the FOM, unlike the PCP it is able to discriminate between rotations with different time ($T$) and parity ($P$) symmetries. The Sagnac geometry implemented here is similar to that used elsewhere to detect non-reciprocal ($\overline{T}P$) rotations like those due to the Faraday effect. Using a Jones matrix approach, novel Sagnac geometries uniquely sensitive to non-reciprocal $\overline{TP}$ (e.g. magneto-electric or magneto-chiral) rotations, as well as to reciprocal rotations (e.g. due to linear birefringence, $TP$, or to chirality, $T\overline{P}$) are proposed.Comment: 12 pages, 7 figure

Biological Active Esters of the Isovaleric Acid

Hydroalkoxycarbonylation of olefins with carbon monoxide and alcohols under condition of homogeneous – catalysis with transition metal complexes allows facile one-step synthesis of practically useful carbon acid esters. Many of them have biological activity and are constituents of drugs or valuable intermediate products in drug synthesis. Hydroalkoxycarbonylation of isobutylene with carbon monoxide and alcohols in the presence of catalytic system Pd(PPh3)4-PPh3-TsOH was applied for preparing of biological active isovaleric acid esters: 1-menthylisovalerate (main active component of the spasmolytic medicine “Validolum”), ethylisovalerate (intermediate product for obtaining sedative and spasmolytic medicines “Ethyl ester of α-bromisovaleric acid” and “Corvalolum”), cyclohexylisovalerate (bactericide activity) and benzylisovalerate (bactericide and antifungus activity). Hydroalkoxycarbonylation reaction of isobutylene with carbon monoxide and alcohols (ethanol, cyclohexanol, l-menthol, benzyl alcohol) in the presence Pd(PPh3)4-PPh3-TsOH system carried out at conditions: temperature 100 ºC; CO pressure 2.0 MPa; reaction time 4 h; reactants and catalyst components ratio [alcohol]:[isobutylene]:[Pd(PPh3)4]:[PPh3]:[TsOH] = 435:550:1:3:12. The yields of the products were 71-95% (on converted alcohols). The selectivity in linear reaction products was 100%. Such a high regioselectivity is apparently provided both by the structure of the starting alkene (isobutylene) and by the reaction mechanism. The most probable is a hydride mechanism. Due to the more advanced technology of production the Medicines will have better qualitative characteristics. The cost of production of the Medicines with the use of new technologies is 2-3 times lower as compared to the medicines produced by existing at the present traditional technologies

The use of Lewis acid AlCl3 as a promoter in the Pd-complex catalytic system of the cyclohexene hydroethoxycarbonylation reaction

This paper presents the results of detailed studies of the possibility of using Lewis acid AlCl3 as a promoter of the catalytic three-component system PdCl2(PPh3)2–PPh3–AlCl3 in the hydroethoxycarbonylation reaction of cyclohexene at low carbon monoxide pressures (2.5 MPa). As a result a high catalytic activity of the three-component system was established and the reaction proceeds regioselectively with the formation of ethyl ether of cyclohexanecarboxylic acid. The optimal conditions of the process have been elaborated (molar ratio of the starting reagents [Cyclohexene]:[Ethanol] = 1:1; molar ratio of the components of the catalytic system = = [PdCl2(PPh3)2]:[PPh3]:[AlCl3] = 1:6:9; carbon monoxide pressure PCO = 2.5 MPa; process temperature T = 120 °C and reaction time τ = 5 h) at which the target product yield reaches 80.7 %. To identify the obtained ethyl ester of cyclohexane carboxylic acid gas chromatographic analysis and mass- and IR- spectra were carried out. Based on the data obtained, a possible mechanism of the reaction route of cyclohexene carbonylation with carbon monoxide and ethanol in the presence of the three-component system PdCl2(PPh3)2–PPh3–AlCl3 is proposed and discussed

Theoretical investigation of a conic-helical loosener for fertilizer applying machine

Rad pokazuje da postojeći uređaji za rasipanje umjetnog gnojiva u granulama u potpunosti ne zadovoljavaju tehničke potrebe. Kako bi se osiguralo postojano i pouzdano doziranje gnojiva potrebno je dokinuti luk iznad izlaza iz lijevka i osigurati prisilni dovod materijala (gnojiva) u napojni (mjerni) uređaj. Cilj istraživanja je odabir optimalnih parametara konično-helikoidnog rasipača uređaja za rasipanje umjetnog gnojiva. Provedena teorijska istraživanja omogućuju uspostavu odnosa između gibanja (brzina i istiskivanje) elementarnih čestica materijala (gnojiva) duž opruga zavojnice i konstrukcije i tehnoloških parametara rasipača (kut između generant i konusne osovine, kut uspona spirale opruga zavojnice, polumjer baze konusa, faktor vanjskog i unutarnjeg trenja, kutna brzina). Variranjem svakog pojedinog parametra može se izabrati njihova optimalna kombinacija ovisno o prihvaćenom kriteriju učinkovitosti rasipača.The paper reveals that the available facilities of granular fertilizer applying do not completely meet the technical requirements. In order to ensure stable and reliable dosing of fertilizers it is necessary to destroy the arch obtained above the hopper outlet and to provide forced feeding of the material (fertilizer) to the feeder (measuring device). The goal of the study is selection of optimum parameters of the fertilizer applying machine conic-helical loosener. The theoretical researches carried out allow to establish the relation between the motion (speed and displacement) of the material (fertilizer) elementary particles along the coils of the springs and the loosener design and technological parameters (the angle between the generant and axis-cones, the helix angle of spring coils, the cone base radius, the coefficients of external and internal friction, the angular speed). By varying each one of the parameters their optimum combination could be selected depending on the accepted loosener efficiency criterion

Limites de détection magnéto-optique pour la spintronique des semi-conducteurs

This work explores the use of the magneto-optical Kerr effect to study conduction electron spin dynamics in non-magnetic semiconductors when pumped with circularly polarized photons. Typically, non-equilibrium, optically-induced magnetic moments in non-magnetic semiconductors are orders of magnitude smaller than those of magnetized materials, including both magnetic and non-magnetic materials in an external magnetic field. The magneto-optical Kerr effect in principal offers sufficient sensitivity to detect such small magnetic moment via a measurement of the Faraday rotation angle of a probe beam in the photon shot noise limit. Three detection configurations have been experimentally compared: partially crossed polarizers, a Sagnac interferometer and an optical bridge. The Sagnac interferometer is shown to be functionally equivalent to partially crossed polarizers, although its sensitivity is compromised by lost photons at each of the obligatory beam splitters present in such a geometry. On the other hand, it has previously been shown that Sagnac interferometers can distinguish between so-called reciprocal and non-reciprocal rotations, and this thesis proposes novel Sagnac geometries to distinguish rotations according to their time and parity symmetries. The optical bridge technique allows for a photon-shot noise limited measurement of the Faraday rotation angle, even with large photon intensities on the detectors, thereby yielding the best possible figure-of-merit. In demonstrations on magnetic materials, a noise floor of a few nrad//√Hz was measured for a probe power of 10 mW. A series of room-temperature, pump-probe Faraday rotation measurements is performed on optically pumped GaAs to compare and contrast this method with standard polarized photo-luminescence techniques. The largest signals are found when the locally probed moment is maximized by strongly focusing the pump and probe beams, and by choosing a probe wavelength tuned to an optical resonance in the electronic structure. Measurements in transverse magnetic field show a Hanle field of 0.43 T, from which the spin lifetime of 88 ps is deduced.Ce travail explore l'utilisation de l'effet magnéto-optique pour étudier la dynamique de spin des électrons de conduction dans les semi-conducteurs non magnétiques lorsqu'ils sont pompés avec des photons polarisés circulairement. En général, les moments magnétiques hors-équilibre induits optiquement dans les semi-conducteurs non magnétiques sont plus petits que ceux des matériaux magnétiques. L'effet magnéto-optique en principe offre une sensibilité suffisante pour détecter ces faibles moments magnétiques via une mesure de rotation Faraday dans la limite de bruit de photons. Nous avons comparés trois méthodes de détection: les polariseurs partiellement croisés, l’interféromètre de Sagnac et le pont optique. L'interféromètre de Sagnac se révèle fonctionnellement équivalent aux polariseurs partiellement croisés, avec une sensibilité diminuée par la perte de photons à chacun des séparateurs de faisceaux nécessairement présents dans cette configuration expérimentale. Par contre, il a été démontré précédemment que les interféromètres de Sagnac permettent de faire la distinction entre les rotations dites réciproques et non réciproques, et cette thèse propose de nouvelles géométries de Sagnac pour distinguer les rotations en fonction de leurs symétries en temps et en parité. La technique du pont optique présente les meilleures performances. Elle permet une mesure de l'angle de rotation de Faraday limitée par le bruit de photons, même avec des puissances lumineuses importantes reçues par les détecteurs, ce qui permet d'obtenir la meilleure figure de mérite possible. Dans les expériences conduites sur des matériaux magnétiques, un bruit de quelques nrad/√Hz a été mesuré pour une puissance de sonde de 10 mW. Une série de mesures de rotation Faraday pompe-sonde à température ambiante a été réalisée sur GaAs pompé optiquement. Les plus grands signaux sont obtenus lorsque le moment magnétique généré et détecté est maximisé en focalisant fortement les faisceaux pompe et sonde et en choisissant une longueur d'onde de la sonde accordée à une résonance optique dans la structure électronique. Les mesures en champ magnétique transversal montrent un champ Hanle de 0.43 T, à partir duquel on déduit la durée de vie de spin de 88 ps

Development of meat products for the nutrition of the elderly

Purpose: Due to the increased risk of diseases and digestive disorders, a balanced diet for the elderly is necessary for their well-being and health. Understanding the effects of meat consumption is especially important for older adults, who can benefit from whole-food protein to compensate for age-related loss of muscle mass and strength. The purpose of this study is to analyse the production of meat products and establish the effect of ostrich meat in the nutrition of the elderly. Methods: The theoretical basis of this study included conclusions and basic recommendations from researchers who explore elderly nutrition, and data from the World Health Organization and the Ministry of Health of the Republic of Kazakhstan. Moreover, research on the nutritional value of ostrich meat pate as a possible component of the diet was conducted, and beef pate was used as a control sample. Results: The study found that ostrich meat pate has a high nutritional value and lower caloric content compared with beef pate, with high protein content and low-fat content. In addition, ostrich pate is very valuable for its content of fatty acids: arachidonic, linoleic, linoleic, and oleic. Conclusion: The findings of the study allow to state that ostrich meat is a dietary and low-calorie product that can be recommended for the elderly. The practical value of the study lies in the optimisation of data on the development of meat products for the nutrition of the elderly and the possible inclusion of ostrich meat in the diet

Helminth parasites of fish of the Kazakhstan sector of the Caspian Sea and associated drainage basin

The northern section of the Caspian Sea is an important fishery for Kazakhstan. In the present study, a total of 606 individuals of 13 fish species were collected. For each of Abramis brama, Alosa saposchnikowii, Atherina boyeri caspia, Carassius auratus, Clupeonella cultriventris, Cyprinus carpio, Liza aurata, Leuciscus aspius, Rutilus rutilus caspius, Sander lucioperca, Sander marinus, and Sander volgensis 50 individuals were examined whilst 6 individuals of Siluris glanis were examined. The nematode parasite Anisakis schupakovi was found in all fish species except Liza aurata, Carassius aurata, Cyprinus carpio and Rutilus rutilus at intensities ranging from 1 to 1197 parasites per infected fish. Trematodes of family Diplostomidae were also isolated from all fish except Alosa saposhnikowii, Clupeonella cultriventris and Sander marinus at intensities ranging from 1 to 242 parasites per infected fish. Other parasites found included the nematodes Porrocaecum reticulatum, Contracecum sp, Camallanus sp and Eustrongylus excisus; the cestodes Neogryporhynchus cheilancristrotus, Bothriocephalus opsariichthydis; the monogenean parasites Mazocraes alosa, Ancyrocephalus paradocus, Gyrodactylus spp, Ligophorus vanbenedenii and Dactylogyrus spp; and the crustacean parasites Ergasilus sp. and Synergasilus sp. In addition one unidentified species of nematode and a bivalve of the genus Unio was recovered from Rutilus rutilus caspius. There was no association between Fulton’s condition index and intensity of parasite infection

Carbonylation of olefins by carbon monoxide and alcohols in the presence of Pd-complex catalytic system

In order to develop new, efficient and environmentally friendly methods for the preparation of practically valuable esters of carboxylic acids, studies of the hydroalkoxycarbonylation reaction of a number of terminal olefins of normal structure (hexene-1, heptene-1, octene-1, nonene-1) with carbon monoxide and alcohols in presence of metal complex catalysts based on palladium phosphine complexes at low carbon monoxide pressures (≤ 20 atm).Two-and three-component systems based on PdCl2 and Pd(Acac)2, PdCl2(PPh3)2, Pd(PPh3)4 complexes containing a free ligand (PPh3) as a stabilizer and Bronsted acid (TsOH) as a promoter were studied as catalysts. It was shown that only the three-component systems PdCl2-PPh3-TsOH, PdCl2(PPh3)2-PPh3-TsOH, Pd(Acac)2-PPh3-TsOH, and Pd(PPh3)2-PPh3-TsOH have the highest catalytic activity in the studied reactions. It was found that the reaction of hydroalkoxycarbonylation of α-olefins proceeds with the formation of a mixture of linear and branched products. The influence of various conditions of the reaction (the ratio of the initial reagents and the components of the catalytic systems, temperature, CO pressure, duration) on the course of the process and on the yield of the target products was investigated. The optimal parameters of the studied reactions have been found

Determination of the main parameters of the photovoltaic solar module

This article deals with the determination of the main operating parameters of a photovoltaic solar module. In laboratory tests, the study of the dependence of current, voltage and power on time and density of solar radiation, as well as monitoring of environmental parameters: temperature and humidity of the outside air. Analysis of the test results shows that a photoelectric module with an installed capacity of 800 W and a total battery capacity of 800 Ah provides the electric power industry with a daily consumption of 2.0 ... 2.2 kWh. The discharge time of the battery varies from 11.7 to 3.5 hours when the average electric load of the consumer changes from 300 to 1000 watts