NITRO CELLULOSE POWDER CHARGES OF LONG SERVICE LIFE: PROBLEMS AND THEIR POSSIBLE SOLUTIONS

2021 ◽  
pp. 33-45
Author(s):  
D. Baulin
Keyword(s):  
Service Life ◽  
Storage Period ◽  
Chemical Transformations ◽  
Energy Characteristics ◽  
Partial Restoration ◽  
Term Operation ◽  
Long Term Storage ◽  
Life Problems ◽  
Physical And Chemical

One of the components of the problem of Ukraine's national security is the loading of warehouses with a variety of ammunition with an expired guaranteed storage period. The experience of storing ammunition shows that during long-term storage, propylene powder used in ammunition is capable of spontaneously undergoing various physical and chemical transformations, which negatively affects the ballistic characteristics of ammunition. The lack of ammunition production in Ukraine has led to the fact that ammunition is currently in operation, the storage time of which reaches 25-30 years or more. This article analyzes publications devoted to scientific research related to the problems of ballistic stability of propellants. A number of factors are presented that affect the physicochemical stability of powder charges during their long-term operation. The generalizing data on changes in the main ballistic characteristics of ammunition at different periods of their storage are presented. It is assumed that one of the ways to improve the ballistic and energy characteristics of ammunition with long service lives can be the regeneration of nitrocellulose powder charges. It is shown that at present there are no methods for the regeneration of propellant charges of long service life. However, there are encouraging data on the treatment of propellants with hydrogen peroxide, on the basis of which a technology can be developed for the complete or partial restoration of the ballistic and energy characteristics of the propellant charge. It is presented that the predictive assessment of changes in the characteristics of ammunition with long service lives does not correspond to their real indicators. It has been determined that the problem of nitrocellulose propellants of long service life is complex and, on the basis of its solution, theoretical and methodological foundations of the regeneration of nitrocellulose propellant charges can be developed to homologate the ballistic and energy characteristics of ammunition.

Influence of Individual Physical and Chemical Indices of Cognacs on their Qualitative Characteristics

2021 ◽  
pp. 34-37
Author(s):  
Екатерина Владимировна Ульянова ◽  
Дарья Владиславовна Андриевская
Keyword(s):  
Phenolic Compounds ◽  
Multicomponent System ◽  
Storage Period ◽  
Alcoholic Beverages ◽  
Long Term Storage ◽  
Organoleptic Characteristics ◽  
Group I ◽  
Calcium Cations ◽  
Entire Storage Period ◽  
Physical And Chemical

Стабильность (розливостойкость) в течение длительного времени - одна из важных составляющих качественных характеристик спиртных напитков виноградного происхождения, в том числе коньяков. Коньяк представляет собой сложную многокомпонентную систему, включающую более 800 различных соединений, в том числе фенольный комплекс древесины дуба и минеральные вещества. В процессе длительного хранения под воздействием ряда факторов эти соединения, вступая во взаимодействие друг с другом, могут образовывать различные виды помутнений, что влечет за собой потерю товарного вида готовой продукции. Целью настоящей работы стало исследование влияния отдельных показателей физико-химического состава обработанных коньяков на изменение их стабильности в процессе хранения. В качестве объектов исследования использовали образцы обработанных розливостойких коньяков отечественного производства, которые были разделены в зависимости от возраста на четыре группы: I группа - 3-летние, 4-летние и 5-летние (23 образца); II группа - выдержанные «КВ» и выдержанные высшего качества «КВВК» (15 образцов); III группа - старые «КС» (9 образцов); IV группа - очень старые «ОС» (7 образцов). Образцы хранили в течение 6 мес. при температуре 22…25 °С, в условиях, не допускающих попадания прямых солнечных лучей. В процессе хранения проводили мониторинг изменения физико-химических показателей, розливостойкости и органолептических характеристик исследуемых образцов с периодичностью 1 раз в месяц. Установлено, что на всем протяжении хранения физико-химические показатели исследованных образцов оставались в пределах нормы. Однако, в отдельных образцах, на определенном этапе эксперимента (после 2 мес. хранения) было отмечено появление осадка. Кроме того, по результатам определения склонности к различным видам помутнений был отмечен рост доли коньяков, нестойких к необратимым коллоидным и кристаллическим помутнениям в трех группах, кроме IV группы. Полученные данные по исследованию структуры осадков и результаты тестов на розливостойкость согласуются с характером изменений массовых концентраций катионов натрия и кальция, а также фенольных соединений. В целом полученные результаты проведенных исследований показали необходимость контроля массовой концентрации катионов натрия и кальция, а также фенольных соединений при прогнозировании розливостойкости коньяков. One of the important components of the quality characteristics of alcoholic beverages of grape origin, including cognacs, is their stability (bottling resistance) for a long time. Cognac is a complex multicomponent system that includes more than 800 different compounds, including the phenolic complex of oak wood and minerals. During long-term storage, under the influence of a number of factors, these compounds, interacting with each other, can form various types of turbidity, which entails the loss of the presentation of the finished product. The aim of this work was to study the effect of individual indicators of the physical and chemical composition of processed cognacs on the change in their stability during storage. As objects of research, we used samples of processed bottling-resistant cognacs of domestic production, which were divided, depending on age, into four groups: Group I - three-year-old, four-year-old and five-year-old (23 samples); Group II - matured «KV» and matured of the highest quality «KVVK» (15 samples); Group III - old «KS» (9 samples); IV group - very old «OS» (7 samples). The samples were stored for 6 months at a temperature of 22…25 °C, in conditions out of direct sunlight. During storage, changes in physical and chemical parameters, bottling resistance and organoleptic characteristics of the samples under study were monitored at a frequency of 1 time per month. It was found that during the entire storage period, the physicochemical indicators of the studied samples remained within the normal range. However, in some samples, at a certain stage of the experiment (after 2 months of storage), the appearance of a precipitate was noted. In addition, according to the results of determining the tendency to various types of cloudiness, an increase in the proportion of cognacs unstable to irreversible colloidal and crystalline cloudiness was noted in three groups, except for group IV. The data obtained on the study of the structure of sediments and the results of tests for pouring resistance are consistent with the nature of changes in the mass concentrations of sodium and calcium cations, as well as phenolic compounds. In general, the results of the studies carried out showed the need to control the mass concentration of sodium and calcium cations, as well as phenolic compounds when predicting the pouring resistance of cognacs.

scholarly journals Dry functional blend with fruit-berry powders for yeast dough

2019 ◽  
Vol 81 (2) ◽  
pp. 177-183
Author(s):  
A. V. Moshkin ◽  
A. T. Vasyukova ◽  
A. E. Alexeyev
Keyword(s):  
Raw Materials ◽  
Long Term Storage ◽  
Chemical Indicators ◽  
Toxicological Studies ◽  
The Russian Federation ◽  
Milk Mixture ◽  
Physical And Chemical ◽  
Term Storage ◽  
High Calorie

The basic information about functional mixtures is outlined, options for compositions and recommendations for use in baking in mass production are proposed. The characteristic of microbiological, physical and chemical indicators is given, and the results of toxicological studies of dry functional mixtures with fruit and berry powders are given. High-calorie, medium-calorie, and low-calorie composite mixtures have been developed for the centralized production of yeast dough. Dry functional mixtures can be produced according to regulatory documents: TU 9161-004-51926638-11 and TI to TU 9161-004-51926638-11. A patent of the Russian Federation No. 2602629 was obtained for dry functional mixtures with fruit and berry powders. The technological scheme for obtaining a dry functional mixture consists of the following operations: sifting, dosing of prescription components in predetermined proportions: dry egg-milk mixture in the amount of 56.2-61.6% sugar – 20.0-24.3% and salt – 14.1-17.2%. Xanthan (1.06-2.43%) or guar (4.25-5.30%) and fruit and berry powders (1.0-1.5%) are introduced as additional raw materials. Then mixing is carried out, preparation for implementation. The resulting mixture is portioned and packaged in paper bags. Fruit and berry powders were prepared from rose hips, aronia, nettle, bananas, apples and carrots. According to microbiological studies, the degree of contamination during storage during the year corresponds to SanPiN 2.3.2.1078-01, which makes it possible to produce dry functional mixtures with fruit and berry powders for long-term storage. They can be stored in a dry, well-ventilated room in compliance with sanitary rules, with a relative humidity of 65-70% and a temperature of 18-20 °C from 0 to 12 months. It was found that during storage for 12 months. in hermetically sealed paper bags, no powder quality changes were observed. Bakery products made using these mixtures can be recommended for medical, preventive and gerontological nutrition.

Interaction of Epididymal Epithelia and their Secretions with Spermatozoa Supports Functional and Morphological Changes During Long-Term Storage in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis)

2020 ◽  
Vol 26 (3) ◽  
pp. 542-550
Author(s):  
Imran Tarique ◽  
Mansoor Tariq ◽  
Xuebing Bai ◽  
Qu Wenjia ◽  
Ping Yang ◽  
...  
Keyword(s):  
Electron Density ◽  
Morphological Changes ◽  
Storage Period ◽  
Sperm Storage ◽  
Synthetic Activity ◽  
High Electron ◽  
Pelodiscus Sinensis ◽  
Clear Cells ◽  
Long Term Storage

AbstractPost-testicular maturation of spermatozoa is crucial for attaining the morphological and functional capabilities needed for successful fertilization. Epididymal epithelia offer a favorable environment for spermatozoa that are stored long term in the turtle epididymis; however, sperm–epithelial interactions during storage, which are enormously important for sperm functional and morphological maturation, are still largely unknown in turtles. The present study examined the epididymis during the sperm-storage period (November–April) in the Chinese soft-shelled turtle (Pelodiscus sinensis). Light and transmission electron microscopy were used to determine the cellular features of each epididymal segment (caput, corpus, and cauda) and their epithelial interactions with the spermatozoa. Spermatozoa were mainly located in the lumena of caput, corpus, and cauda epididymides. Numerous spermatozoa were bound to apical surfaces of the epithelia, and several were even embedded in the epithelial cytoplasm of the caput and corpus epididymides. No embedded spermatozoa were found in the cauda epididymis. In all epididymal segments, principal and clear cells showed the synthetic activity, evidenced by a well-developed endoplasmic reticulum network and high and low electron-dense secretory materials, respectively. Principal and clear cells in the caput and corpus segments showed embedded spermatozoa in electron-dense secretions and in the lipid droplets within the cytoplasm. No lysosomes were observed around the embedded spermatozoa. The lumena of the caput and corpus segments showed few apocrine and low electron density secretions. In the lumen of the cauda epididymidis, different secretions, such as holocrine with low and high electron density and their fragmentation, apocrine, and dictyosome, were found and are summarized. Altogether, sperm physical interactions with secretions either in the cytoplasm of epithelium or in the lumen may support the viability, morphological maintenance, and transfer of various proteins involved in long-term sperm storage in the turtle. This interaction could help us to understand the mechanisms of long-term sperm storage and provide more insights into the reproductive strategies of turtle sperm preservation.

Fatigue Strength and Metal Condition in the Context of Gas Turbine Buckets Life Extension

2012 ◽  
Author(s):  
Sergey A. Ivanov ◽  
Alexander I. Rybnikov
Keyword(s):  
Fatigue Strength ◽  
Service Life ◽  
Gas Turbine ◽  
Fatigue Resistance ◽  
Gas Turbines ◽  
Life Extension ◽  
Term Operation ◽  
Life Estimation ◽  
Metal Properties

Criteria for remaining life estimation and methods for enhancing fatigue resistance of heavy-duty gas turbine bucket metal are based on the analysis of changes in the structure and properties of metal after long-term operation. High-cycle fatigue (HCF) resistance is shown to be a decisive characteristic in the residual life estimation of turbine buckets after operation over 100,000 hours. The tests of the buckets from cast and wrought nickel-based alloys after long-term operation demonstrated decreasing of fatigue strength by up to 25%. The metal structure in operation undergoes notable deterioration mainly in phase redistribution. The size and configuration of metal phases are changing also. It caused the changes in metal properties. The decrease of the bucket fatigue strength correlates with the decrease of metal ductility. The reconditioning heat treatment resulted in restoring mechanical properties of metal. The fatigue resistance also increased nearly to the initial level. The influence of operational factors on bucket fatigue strength deterioration has been established. The mechanical damages on bucket airfoil may decrease the fatigue resistance. We found the correlation of endurance limit and damages depth. The procedures for metal properties recovering and buckets service life substantial extension have been developed. It has resulted in the extension of the buckets service life by up to 50% over the assigned life in gas turbines operated by Gazprom.

scholarly journals Properties of Fiberboard Overpack Material in the 9975 Shipping Package Following Thermal Aging

2007 ◽  
Author(s):  
W. L. Daugherty
Keyword(s):  
Service Life ◽  
Physical Properties ◽  
Thermal Aging ◽  
Impact Resistance ◽  
Storage Conditions ◽  
Radioactive Material ◽  
Long Term Storage ◽  
Term Storage ◽  
Over Time

Many radioactive material shipping packages incorporate cane fiberboard overpacks for thermal insulation and impact resistance. Mechanical, thermal and physical properties have been measured on cane fiberboard following thermal aging in several temperature/humidity environments. Several of the measured properties change significantly over time in the more severe environments, while other properties are relatively constant. These properties continue to be tracked, with the goal of developing a model for predicting a service life under long-term storage conditions.

Maintenance and Support of Hydraulic Thrust Vector Control Systems for Long-Term Unattended Storage

1963 ◽  
Vol 85 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Nicholas N. Fruktow ◽  
Leo E. Gatzek
Keyword(s):  
Vector Control ◽  
Control Systems ◽  
Storage Period ◽  
General Nature ◽  
Thrust Vector Control ◽  
Long Term Storage ◽  
Ballistic Missiles ◽  
Operational Readiness ◽  
Thrust Vector

Second-generation ballistic missiles are being developed for compatibility with the concept of long-term storage in permanent underground housing, with missiles in firing position, and in a condition of full operational readiness. It is intended that operational status be maintainable without major interruption over a three-year storage period. This report investigates the various factors which are considered to significantly influence the capability of hydraulic thrust vector control systems to remain in a state of operational readiness when subjected to such periods of inert storage as components of total missile configurations. The following sections present a detailed outline of technical difficulties which may be encountered, information and data resulting from applicable test programs, and the general nature of solutions to apparent problems. The design concept of a storable hydraulic thrust control system is considered to be feasible, but may be effectively achieved only by fulfillment of certain stringent design requirements and by further development of preservation techniques to preclude the need for in-field maintenance.

scholarly journals DEGRADATION DAMAGE OF REINFORCED CONCRETE FRAME IN LONG-TERM EXPLOITATION

2021 ◽  
Vol 9 (4) ◽  
pp. 11-15
Author(s):  
Mikhail Berlinov ◽  
Marina Belinova ◽  
Roman Korol ◽  
Aleksandr Tvorogov
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Phenomenological Theory ◽  
Reinforced Concrete Frame ◽  
Term Operation ◽  
Concrete Frame ◽  
Aggressive Environment ◽  
Real Work ◽  
Combined Action

A method for calculating a reinforced concrete frame under rheological deformation conditions is proposed, taking into account degradation damage as a result of corrosion during long-term operation, reflecting their real work under the combined action of a load and an aggressive environment based on the modern phenomenological theory of deformation of an elastic-creeping body. The possibility of considering the processes of long-term deformation of reinforced concrete in conditions of long-term exploitation is shown. Analytical dependencies and a calculated example are given for the considered service life.

scholarly journals Effect of nanosized calcium and magnesium particles on absorption in peach tree leaves

2021 ◽  
Author(s):  
Jae-Ryoung Park ◽  
Yoon-Hee Jang ◽  
Il Kyung Chung ◽  
Kyung-Min Kim
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Prunus Persica ◽  
Storage Period ◽  
Magnesium Content ◽  
Long Term Storage ◽  
Short Period ◽  
Calcium And Magnesium ◽  
Peach Trees

Plants require a variety of elements to grow. Of these, calcium and magnesium play an important role in strengthening the cell wall. Although peaches (Prunus Persica) are highly preferred by consumers, they ripen quickly and become soft over a relatively short period of time after harvesting, making them difficult to transport and store. In addition, the ripening process of peaches proceeds very quickly. In addition, cell walls are weakened during maturation, and various pathogens can easily grow, causing rapid decay. Therefore, yield loss occurs during long-term storage or transport. To increase the storage period, a method to delay softening action is required. One potential means to improve firmness is improve calcium and magnesium content as these elements make up and strengthen cell walls. However, calcium and magnesium are not readily absorbed by plants. In this study, the size of calcium and magnesium particles were reduced to less than 900 nm via grinding and their absorption rates were evaluated in the leaves of peach trees. When plant nutrients with a small particle size by nanotechnology were sprayed on peach trees, the content of calcium and magnesium was increased in the petioles, adaxial, abaxial, and leaf side. Therefore, a reduction in the particle size of calcium and magnesium increases the absorption rate in peach leaves.

scholarly journals The Influence of 1-Methylcyclopropene on `Cortland' and `McIntosh' Apple Quality Following Long-term Storage

HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1062-1065 ◽  
Author(s):  
John M. DeLong ◽  
Robert K. Prange ◽  
Peter A. Harrison
Keyword(s):  
Shelf Life ◽  
Storage Period ◽  
Titratable Acidity ◽  
Soluble Solids ◽  
Long Term Storage ◽  
Solids Content ◽  
Apple Quality ◽  
Term Storage

`Redcort Cortland' and `Redmax' and `Summerland McIntosh' apples (Malus ×domestica Borkh.) were treated with 900 nL·L-1 of 1-methylcyclopropene (1-MCP) for 24 hours at 20 °C before storage and were kept at 3 °C in either a controlled atmosphere (CA) of 2 kPa O2 and <2.5 kPa CO2 or in an air (RA) environment for up to 9 months. After 4.5 months, half of the fruit were treated with a second 900 nL·L-1 1-MCP application in air at 3 °C for 24 hours and then returned to RA or CA storage. At harvest and following removal at 3, 6, and 9 months and a 7-day shelf life at 20 °C, fruit firmness, titratable acidity (TA) and soluble solids content (SSC) were measured, while internal ethylene concentrations (IEC) in the apple core were quantified after 1 day at 20 °C. Upon storage removal and following a 21-day shelf life at 20 °C, disorder incidence was evaluated. 1-MCP-treated apples, particularly those held in CA-storage, were more firm and had lower IEC than untreated fruit. Higher TA levels were maintained with 1-MCP in all three strains from both storages, while SSC was not affected. Following the 6- and/or 9-month removals, 1-MCP suppressed superficial scald development in all strains and reduced core browning and senescent breakdown in RA-stored `Redmax' and `Summerland' and senescent breakdown in RA-stored `Redcort'. 1-MCP generally maintained the quality of `Cortland' and `McIntosh' fruit held in CA and RA environments (particularly the former) to a higher degree than untreated apples over the 9-month storage period. A second midstorage application of 1-MCP at 3 °C did not improve poststorage fruit quality above a single, prestorage treatment.

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