3,802 research outputs found
Particle size distribution analysis of pine sawdust: comparison of traditional oscillating screen method and photo-optical analysis
ArticleParticle size and particle size distribution (PSD) are crucial parameters which affect properties of particulate and agglomerated materials, and have an impact on a quality and utilization of a final product. The aim of this paper was to determine PSD as well as to assess dimensional features of pine sawdust fractions via mechanical sieve analysis and photo-optical analysis. The first one is a traditional and standard method taking into account only one parameter of particle shape and the second one is a modern method based on a digital image processing that considers also irregular shapes of biomass particles. Pine sawdust was grinded into three fractions: 4, 8 and 12 mm and analysed using two mentioned methods. A horizontal vibrating sieve shaker comprising 11 sieves and a bottom pan was used, and the obtained data of retained particles on each sieve were evaluated. For comparison, a computerized photo-optical particle analyser was applied with max Feretβs diameter as a measurement algorithm for a particle length, and PSD was analyzed by grouping the particles according to their distinct lengths adjusted to the sievesβ sizes used in the screening method. Moreover, additional results in dimensions and parameters of PSD were obtained and evaluated through the photo-optical method. Pine sawdust particles can be described as non-uniform, mainly prolonged, finer particles dominated in all fraction samples. The study showed differences in the results, inaccuracy and other drawbacks of the conventional sieving method such as clogging and falling-through phenomena as well as the limitations of the machine vision. Strong sides of both methods were discussed, too. Overall, the results contributed to a better knowledge of the material properties and different methods of PSD analysis
Black Hole Formation in X-Ray Binaries: The Case of XTE J1118+480
In recent years, an increasing number of proper motions have been measured for Galactic X-ray binaries. When supplemented with accurate determinations of the component masses, orbital period, and donor luminosity and effective temperature, these kinematical constraints harbor a wealth of information on the systems' past evolution. The constraints on compact object progenitors and kicks derived from this are of immense value for understanding compact object formation and exposing common threads and fundamental differences between black hole and neutron star formation. Here, we present the results of such an analysis for the black hole X-ray binary XTE J1118+480. We present results from modeling the mass transfer phase, following the motion in the Galaxy back to the birth site of the black hole, and examining the dynamics of symmetric and asymmetric core-collapses of the black hole progenitor
Risk assessment in the formation of motivational programs aimed at retaining the heads of organizations
The relevance of the study is determined by the increasing role of risks in the formation of motivation programs aimed at retaining managers of the middle and top levels of organization management. The purpose of the study was to identify risks that arise in the process of implementing motivation programs for managerial personnel. In the study, the following tasks were solved: determining the sources and risk factors; assessing the probability of risks and the level of possible consequences of a risk event; identifying the risks that are most priority for management based on building a risk map; development of ways to reduce risks that reduce the effectiveness of the implementation of motivational programs to retain managers of the organization. The work uses systematic and situational approaches, expert assessment, the survey method and the Delphi method, risk mapping. The developed measures to eliminate risks will allow organizations to prevent reputational and financial losses and analyze the effectiveness of each implemented motivational tool to retain the leaders of the organization
Research on solid biofuels from cotton waste biomass β alternative for Tajikistanβs energy sector development
ArticleAn increasing awareness of the negative environmental cost associated with the
combustion of fossil fuels and concerns over the geopolitical instability of the main oil producing
regions is driving the development of renewable energy sources and biofuels. Use of solid
biofuels made of different types of biomass became perspective alternative to conventional fuels
in many countries. Such positive indicators as low cost of the final product that meets the quality
of standards, not capital intensive production, possibility of producing briquettes/pellets from
almost any agricultural waste or combination of raw materials are undoubted advantages of
biomass based fuels. The main challenges for Tajikistanβs energy sector, which is depended on
energy imports, are: to increase energy supply through better exploitation of hydropower and
other renewable energy sources such as wind, solar and primary biofuels. Within the agricultural
sector of Tajikistan, which is highly agrarian country, cotton accounts for 60% of agricultural
output. According to the Ministry of Agriculture of Tajikistan 199,400 hectares of lands have
been allocated to cotton cultivation in the year of 2014. Plenty of unused cotton residual biomass
could be effectively utilized for winter heating in rural areas. The main focus of the research was
to investigate and assess physical, chemical and mechanical properties of pellets and briquettes
produced form cotton waste biomass
Customs business: lecture notes
The textbook contains the main materials related to the course of the lecture on the subject "Customs business ". The purpose of this synopsis is to help students master the basic aspects of customs taxation, customs control, etc. It is intended for students majoring in 051 "Economics" in the specialty "International Economics", bachelor's degree in full-time Kyiv Polytechnic Institute named after Igor Sikorsky. Designed for all higher education institutions, as well as teachers, graduate students and specialists dealing with customs taxation and control, as well as entrepreneurs and citizens operating in Ukraine and abroad
PSYCHOTIC DISORDERS IN PEOPLE USING SYNTHETIC CANNABINOIDS (SPICE)
The study involved the group of patients (n = 40) with psychotic disorders who used synthetic cannabinoids (spice). Among the psychotic disorders according to ICD-10 we allocated intoxication delirium (F12.03; 35 %), schizophreniform disorder (F12.50; 60 %), disorder with predominantly manic psychotic symptoms (F12.55; 5 %). The average age of patients was 25.2 Β± 4.4 years. Hereditary aggravation in patients who consume synthetic cannabinoids was presented by alcoholism and substance abuse (20 %), affective disorders (7.5 %), schizophrenia (5 %); personality disorders (10 %); suicides (2.5 %). The group of patients with intoxication with delirium had significantly higher frequency of family history of alcoholism and addiction to psychoactive substances compared with patients with schizophreniform disorder (p < 0.02). Clinic intoxication delirium was characterized by disturbance of consciousness (delirium, twilight) lasting from several hours to 2-3 days, psychomotor agitation, aggression, shouting certain phrases and words, anxiety, fear, visual hallucinations. In patients with acute schizophreniform disorder (24 patients; 60 %) symptoms consisted of a dominant affect (depressive, or mixed), productive psychopathological symptoms within the list of F20 headings of ICD-10. Productive syndromes were limited to verbal hallucinosis (true or its limiting variants) in the form of voiced (which discuss the patient's behavior, threaten him/her with death, offer advice), reference of persecutory delusion. The coming out of a psychotic state was characterized by short-term postpsychotic depression. Patients received detoxification therapy and also combined psychopharmacotherapy with the use of antipsychotics, antidepressants, tranquilizers, normotymics, nootropics
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