О некоторых особенностях структуры участков коры выветривания серпентинитов Кемпирсайского массива

New diode laser devices use the modular character of diode lasers to form beam shapes that are adapted to the processing task. In this paper cutting and welding applications of these tools are presented. A linear laser line is applied for the cutting-to-length of coil material. Diode laser modules that form an annular laser spot are utilized for optical flame cutting of steel material and simultaneous welding of annular seams. Furthermore, cutting of thin materials with a diode laser cutting plotter device is demonstrated. Moreover, new results of welding experiments with commercial diode lasers are presented

Модельное программное обеспечение системы аварийного спасения перспективного транспортного корабля нового поколения

The laser beam fusion cutting process is described with a three-dimensional free boundary problem for the motion of one phase boundary. Its variational formulation is presented. An ODE approximation of the PDE problem is derived, which describes the dynamics of the process by means of characteristic dynamical variables: the position of the boundary, the heat content within the material and the surface temperature. For the spatially one-dimensional case an analytical solution of the PDE problem is presented and the accuracy of the corresponding ODE approximation is investigated. Analysis of the ODE approximation revealed the separation of time scales for the dynamics of the boundary and the heat content. The results of the time scale separation and the nonlinear response of the cutting process onto external modulation of the processing parameters are compared with the experimental measurements of the thermal emission

Possible explanations for different surface quality in laser cutting with 1 micron and 10 microns beams

In laser　cutting　of　thick　steel　sheets,　quality　difference　is　observed　between　cut　surfaces　obtained　with 1 micron and 10 micron laser beams. This paper investigates physical mechanisms for this interesting and important problem of the wavelength dependence. First, striation generation process is described, based on a 3D structure of melt flow on a kerf front, which was revealed for the first time by our recent experimental observations. Two fundamental processes are suggested to explain the difference in the cut surface quality: destabilization of the melt flow in the central part of the kerf front and downward displacement of discrete melt accumulations along the side parts of the front. Then each of the processes is analyzed using a simplified analytical model. The results show that in both processes, different angular dependence of the absorptivity of the laser beam can result in the quality difference. Finally we propose use of radial polarization to improve the quality with the 1 micron wavelength

Применение треугольной схемы расположения скважин для добычи урана из малого изометрического рудного тела

The dynamical behaviour of the laser beam fusion cutting process of metals is investigated. Integral methods such as the variational formulation are applied to the partial differential equations for the free boundary problem and a finite dimensional approximation of the dynamical system is obtained. The model describes the shape of the evolving cutting kerf and the melt flow. The analysis is aimed at revealing the characteristic features of the resultant cut, for example, ripple formation and adherent dross. The formation of the ripples in the upper part of the put, where no resolidified material is detectable, is discussed in detail. A comparison with numerical simulations and experiments is made

A postmodern approach to ecological sustainability : the re-enchantment of Fiji's forests

"Na cava na i sau ni taro ni kena tamusuki na veikau e Viti?”, a vuqa era taroga. Au nanuma ni bibi cake na taro. Kevaka e cala na veitaro e tarogi sa dredre sara me kunei na kena i sau a veiganiti. E gadrevi li me vakavinakataki na kena vakatulewataki? Se na navunavuci vinaka li? Na bula toro cake vakailavo li? Se na i tovo vakavanua? Au nanuma ni vu ni nodra vakacacana na tamata na veika e tu tikivi keda a Viti me vaka na musu kau e vakatau mai na noda i tovo vakavanua. Ia na mataqali tovo vakavanua cava a tokoni e Viti me baleta na kena i tuvaki ni vanua, se tiki ni tovo cava e cala? E Viti e kunei kina na bula veimaliwai ni veimatatamata, ia sa bula ka donumaka e dua na gauna ni veisau you. Na veisau vovou sa kena i tovo na kila ka, kei na i tovo e bucini cake ena yavu ni vakasama e taucoko. Na veisau vovou sa veisautaka na i rairai ni vanua e Viti ka kidomoka na veika kece e vakamareqeti ki na dua na kena yaga e qiqo. Ia, na tamusuki ni vaikau sa vakayacori makawa e Viti ni bera na gauna ni veisau oqo, e na gauna ni bula va-Koloni, ka sa dodonu me rau beitaki ruarua na i tovo e rua oqo. Na nona dusi e dua me beitaki ena sega ni vukea na leqa, ia na veika e rawa ni vakayacori sa i koya na noda taqomaki keda mai na noda vakalecalecava ni sega ni cala na i tovo ena kena vakacacani na veika e tu tikivi keda. Na vei tovo kece sara e dodonu me ra vakaitavi ena kena kunei na bula toro caki. Na i vakarau ena sega ni vunitaki dua mai na i tavi me qaravi. Na kena rawati na i naki ni nodra karoni me tudei na veika bula e tu tikivi keda sa gadrevi kina na vakatulewa matau ka ni veika e dau yaco e sega ni vaka i vakarau. Sa gadrevi talega kina na i tovo ka sega ni okata na kila ka me gaunisala duadua ni kena veivosakitaki na i tuvaki ni vanua. Na kena vakaduavatataki ni veivakasama kei na rokovi ni veika tawa kilai vakakina na veika e tawa siqemi rawa sa rawa ni kunei ena vuqa na i tovo, ka okati kina na vei tovo makawa vaka-Viti kei na nodra na vavalagi. Kevaka e vakasaqarai dina me tudei tu na vanua era bula voli kina na veika bula tikivi keda, na i tavi e tu sa i koya na kena vakasaqarai se kunei vou tale eso na veivakasama vovou kei na kena vakauqeti na nodra bula vakataki ira ga na veika bula. "What is the answer to deforestation in Fiji?" many people are asking. To find an answer we first need a question. If the wrong question is asked the possibility of an appropriate answer is out of reach. Is better management needed? Is it better planning? Perhaps it is a greener economy? Or is it culture? I argue that the causes of human induced environmental degradation in Fiji such as deforestation lie in the character of culture. But what culture or cultures do the landscapes of Fiji support, and what aspect of culture is at fault? Fiji is culturally diverse but currently dominated by modernity. Modernity is a culture of knowledge, and a culture built upon the foundations of a steady state rationality. Modernity has disenchanted the landscapes of Fiji and squeezed all forms of value into the narrow framework of utility. However, deforestation also happened in Fiji before modernity arrived with the colonial British, and so both pre-modern and modern cultures in Fiji must share the blame. Pointing at someone to blame does not solve our problem, but what it can do is prevent us from pretending that cultures are innocent when it comes to environmental disharmony. All cultures are responsible for enacting a sustainable life. Tradition will not hide anyone from that responsibility. Fulfilling the obligation of ecological sustainability requires a rationality of process because reality is in a constant state of flux. It also requires a culture that does not see knowledge as the only way of engaging in a conversation about or with a landscape. A rationality of process and a respect for the unknown and unknowable can be found in many different cultures, including the non-modern Fijian culture and non-modern cultures in the West. If ecological sustainability is what is sought, the task is a discovery or re-discovery of process thinking and a re-enchantment of Nature

The Effect of Ethanol on the Release of Opioids from Oral Prolonged-Release Preparations

Recent experience has prompted the US FDA to consider whether ethanol ingestion may modify the release characteristics of prolonged-release formulations, where dose dumping may be an issue for patient safety

The efficacy and safety of prokinetic agents in critically ill patients receiving enteral nutrition: a systematic review and meta-analysis of randomized trials.

BACKGROUND: Intolerance to enteral nutrition is common in critically ill adults, and may result in significant morbidity including ileus, abdominal distension, vomiting and potential aspiration events. Prokinetic agents are prescribed to improve gastric emptying. However, the efficacy and safety of these agents in critically ill patients is not well-defined. Therefore, we conducted a systematic review and meta-analysis to determine the efficacy and safety of prokinetic agents in critically ill patients. METHODS: We searched MEDLINE, EMBASE, and Cochrane Library from inception up to January 2016. Eligible studies included randomized controlled trials (RCTs) of critically ill adults assigned to receive a prokinetic agent or placebo, and that reported relevant clinical outcomes. Two independent reviewers screened potentially eligible articles, selected eligible studies, and abstracted pertinent data. We calculated pooled relative risk (RR) for dichotomous outcomes and mean difference for continuous outcomes, with the corresponding 95 % confidence interval (CI). We assessed risk of bias using Cochrane risk of bias tool, and the quality of evidence using grading of recommendations assessment, development, and evaluation (GRADE) methodology. RESULTS: Thirteen RCTs (enrolling 1341 patients) met our inclusion criteria. Prokinetic agents significantly reduced feeding intolerance (RR 0.73, 95 % CI 0.55, 0.97; P = 0.03; moderate certainty), which translated to 17.3 % (95 % CI 5, 26.8 %) absolute reduction in feeding intolerance. Prokinetics also reduced the risk of developing high gastric residual volumes (RR 0.69; 95 % CI 0.52, 0.91; P = 0.009; moderate quality) and increased the success of post-pyloric feeding tube placement (RR 1.60, 95 % CI 1.17, 2.21; P = 0.004; moderate quality). There was no significant improvement in the risk of vomiting, diarrhea, intensive care unit (ICU) length of stay or mortality. Prokinetic agents also did not significantly increase the rate of diarrhea. CONCLUSION: There is moderate-quality evidence that prokinetic agents reduce feeding intolerance in critically ill patients compared to placebo or no intervention. However, the impact on other clinical outcomes such as pneumonia, mortality, and ICU length of stay is unclear

Polymorphism in the oxytocin promoter region in patients with lactase non-persistence is not related to symptoms

<p>Abstract</p> <p>Background</p> <p>Oxytocin and the oxytocin receptor have been demonstrated in the gastrointestinal (GI) tract and have been shown to exert physiological effects on gut motility. The role for oxytocin in the pathophysiology of GI complaints is unknown. The aim of this study was to examine genetic variations or polymorphism of oxytocin (<it>OXT</it>) and its receptor (<it>OXTR</it>) genes in patients with GI complaints without visible organic abnormalities.</p> <p>Methods</p> <p>Genetic variants in the <it>OXT </it>promoter region, and in the <it>OXTR </it>gene in DNA samples from 131 rigorously evaluated patients with Irritable Bowel Syndrome (IBS), 408 homozygous subjects referred for lactase (LCT-13910 C>T, rs4988235) genotyping, and 299 asymptomatic blood donors were compared. One polymorphism related to the <it>OXT </it>gene (rs6133010 A>G) and 4 related to the <it>OXTR </it>gene (rs1465386 G>T, rs3806675 G>A, rs968389 A>G, rs1042778 G>T) were selected for genotyping using Applied Biosystems 7900 HT allele discrimination assays.</p> <p>Results</p> <p>There were no statistically significant differences in the genotype or allele frequencies in any of the SNPs when IBS patients were compared to healthy controls. Among subjects referred for lactase genotyping, the rs6133010 A>G <it>OXT </it>promoter A/G genotype tended to be more common in the 154 non-persistent (27.3%) subjects than in the 254 lactase persistant (18.1%) subjects and in the healthy controls (19.4%) (p = 0.08). When direct comparing, the A/G genotype was less common in the <it>OXT </it>promoter region in controls (p = 0.09) and in subjects with lactase persistence (p = 0.03) compared to subjects with lactase non-persistence. When healthy controls were viewed according to their own LCT-13910 genotypes, the C/C lactase non-persistent controls had a higher frequency for the <it>OXT </it>promoter A/G genotype than LCT-13910 T/T lactase persistent controls (41.2% vs 13.1%).</p> <p>No significant differences in frequencies of the investigated <it>OXTR </it>SNPs were noted in this study.</p> <p>Conclusion</p> <p>The results suggest that polymorphism in the promoter region of the <it>OXT </it>gene is most common in subjects with lactase non-persistence. This polymorphism may not be related to GI symptoms, as it is related to lactase non-persistence also in healthy controls.</p

Laser beam cutting - A mature and still advancing laser application becomes calculable

Laser cutting models provide solutions, varying from analytical steady-state equations based on singular physical sub-processes easily to be calculated, to fully numerical time dependent simulations requiring several days for the calculation of a single cut. In order to solve this dilemma CALCut calculates the three-dimensional, steady-state process including all relevant sub-processes by a combination of semi-analytical and semi-numerical algorithms. Systematic parameter screening is enabled