Establishing the conditions for the formation of a near-wall layer of solid granular fill of a rotating drum

This paper reports the assessment of the influence of dynamic motion parameters on the formation and disappearance at the cylindrical surface of the chamber of the rotating drum of the near-wall layer of non-loose granular fill. Based on the results of experimental visualization of the flow, the effect of solidity on the behavior of granular fill was revealed. The hydrodynamic effect of fill quasi-liquefaction under the action of solidity has been established, which involves the occurrence of a connecting interaction between adjacent layers and the surface of the chamber. Conversion of shear circulation flow to homogeneous dense clustered stream with slipping and rolling without relative movement of particles was detected. The hydrodynamic characteristics of circulation flow transition to the near-wall layer mode during rotation acceleration have been defined. Such a transition is implemented by smoothly increasing the thickness of the layer when the rest of the fill is circulated at the bottom of the chamber. The effect of the rheological hysteresis of the movement of the rotating chamber fill, caused by quasi-liquefaction of non-loose granular environment, has been established. The effect implies exceeding the speed limit ωfl in the formation of a near-wall layer, at rotation acceleration, above the boundary ωdl of the layer disappearance when the rotation slows down. The manifestation of hysteresis mainly increases with an increase in Reynolds number. The intensity of increased hysteresis manifestation increases with a decrease in the degree of filling the chamber. The value of the Froud number for the ωfl and ωdl boundaries increases with the increase in Re. It has been established that at the relative particle size of the dispersed fill ψdc≈(0.065–1.04)·10‑3 and Re=30–500, Fr=1–2.9, for the ωfl boundary, and Fr=0.5–1.4, for the ωdl boundary. The Fr value for the ωfl limit was found to exceed this value for the ωdl boundary by 1.6–2.1 times. The established effects make it possible to substantiate the rational parameters for the grinding process in drum-roll mills

Design of an apparatus for low-temperature processing of meat delicacies

Culinary meat products, in particular, delicacies, account for a significant share of the diet in many countries of the world, predetermining the need to introduce innovative solutions for the production of products of a wide range of use with original taste properties. A structure of the device for low-temperature processing of meat delicacies involving the heating of the working surface with a flexible film resistive electric heater of radiative type has been developed. Temperature control is carried out with a needle thermocouple. That makes it possible to cool the delicacy to 25...30 °C by autonomous fans during the conversion of secondary thermal energy by Peltier elements. It was established that the low voltage at the temperature of 70...80 °C is 4...6 W, and, at 25...30 °C, it is, respectively, 1.5...3 W. A comparative analysis has been performed of the heat treatment of meat delicacy in the traditional way and in the developed apparatus upon reaching 71...75 °C inside the product. The temperature for a traditional machine, after 5 minutes of processing, is 15...17 °C at the contact surface and 8 °C at the center. For the model structure, the temperature of the contact surface is 7...8 °C, and 4...5 °C in the center. After 25 minutes of processing in the traditional way, the temperature in the center was 17...18 °C, in the near-wall layers ‒ 60 °C. In the model structure, 8...9 °C, at a temperature of the near-wall layers of 25 °C. The temperature difference from the center to the near-wall layer, depending on the processing time in the traditional way, ranges from 10 to 50 °C, and, in the model apparatus, from 4 to 24 °C. The model device provides a uniform heat supply under conditions of achievement of 71…75 °C in the center of a product with a reduction of specific cost by 2.6 times in comparison with a traditional technique. The ham prepared in the developed apparatus is characterized by uniform coloration, juiciness, and natural original taste

Mathematical Modeling and Optimization of Fused Filament Fabrication (FFF) Process Parameters for Shape Deviation Control of Polyamide 6 Using Taguchi Method

Fused filament fabrication (FFF) is a layer-by-layer additive manufacturing (AM) process for producing parts. For industries to gain a competitive advantage, reducing product development cycle time is a basic goal. As a result, industries’ attention has turned away from traditional product development processes toward rapid prototyping techniques. Because different process parameters employed in this method significantly impact the quality of FFF manufactured parts, it is essential to optimize FFF process parameters to enhance component quality. The paper presents optimization of fused filament fabrication process parameters to improve the shape deviation such as cylindricity and circularity of 3D printed parts with the Taguchi optimization method. The effect of thickness, infill pattern, number of walls, and layer height was investigated as variable parameters for experiments on cylindricity and circularity. The MarkForged® used Nylon White (PA6) to create the parts. ANOVA and the S/N ratio are also used to evaluate and optimize the influence of chosen factors. As a result, it was concluded that the hexagonal infill pattern, the thickness of 5 mm, wall layer of 2, and a layer height of 1.125 mm were known to be the optimal process parameters for circularity and cylindricity in experiments. Then a linear regression model was created to observe the relationship between the control variables with cylindricity and circularity. The results were confirmed by a confirmation test.

Spatial fungal community diversity profiles in pit mud samples from fermentation cellars used to manufacture Chinese Strong-flavour liquor

Background Few studies to date have sought to characterize the spatial profiles of pit mud microbial communities in fermentation cellars from Chinese strong-flavour liquor distilleries. This study was thus designed to evaluate these eukaryotic communities in pit mud samples via a multidimensional DGGE approach and by assessing associated sample physicochemical properties. Results Penicillium fuscoglaucum, Penicillium glandicola, Aotearoamyces nothofagi, Malassezia restricta, Penicillium lanosocoeruleum, Penicillium crustosum, and Aspergillus tonophilus were detected only in pit mud from the upper cellar wall, while Alternaria alstroemeriae, Trichosporon insectorum, Fusarium equiseti, Calonectria pseudoreteaudii, Penicillium clavigerum, Penicillium compactum, Ascochyta phacae, Metarhizium frigidum, Alternaria burnsii, Fusarium nurragi, and Didymella keratinophila were present only in the middle cellar wall layer. Alternaria zantedeschiae and Ilyonectria cyclaminicola were only present in pit mud samples from the lower cellar wall, while Leptobacillium leptobactrum, Calonectria queenslandica, Aspergillus appendiculatus, and Candida pseudolambica were only detected in pit mud from the cellar bottom. Moisture, pH, PO43−, acetic acid, humus, K+, Mg2+, Ca2+, acetic acid, butyric acid, and caproic acid levels in these different pit mud positions exhibited a rising incremental pattern from the upper wall layer to the bottom layer, whereas lactic acid levels were significantly lower in the bottom pit mud layer relative to other layers. Conclusions A clear relationship between fungal community structure and physicochemical variables in different spatial pit mud samples, especially moisture, pH, and NH4+-N were identified as the three most significant factors associated with fungal community through a redundancy analysis.

EVALUATION OF THE FEATURES OF THE STRUCTURE OF WATER AND AQUEOUS SOLUTIONS NEAR A SOLID SURFACE

The paper evaluates changes in the structure of water and aqueous solutions of sodium chloride in the wall layer on the basis of dielectrometry and correlation analysis. It is shown that when the distance to the solid surface decreases, there is a multi-fold nonlinear decrease in the electrical capacitance and a nonlinear change in the Sr parameter, which characterizes the magnitude of the change in the electrical capacitance of the conduction fluid when the distance to the solid surface changes. The parameters used in the work (electric capacity of liquids and Sr ) can be used to evaluate the changes in the structural organization of aqueous solutions in the wall (boundary) layer and to interpret the processes occurring in the liquid layer at the interface of the solid – aqueous solution phases.

Exploration of synergistic action of cell wall-degrading enzymes against Mycobacterium tuberculosis

Background The major global health threat tuberculosis is caused by Mycobacterium tuberculosis (Mtb). Mtb has a complex cell envelope – a partially covalently linked composite of polysaccharides, peptidoglycan and lipids, including a mycolic acid layer – which conveys pathogenicity but also protects against antibiotics. Given previous successes in treating gram-positive and -negative infections with cell wall degrading enzymes, we investigated such approach for Mtb. Objectives (i) Development of an Mtb microtiter growth inhibition assay that allows undisturbed cell envelope formation, to overcome the invalidation of results by typical clumped Mtb-growth in surfactant-free assays. (ii) Exploring anti-Mtb potency of cell wall layer-degrading enzymes. (iii) Investigation of the concerted action of several such enzymes. Methods We inserted a bacterial luciferase-operon in an auxotrophic Mtb strain to develop a microtiter assay that allows proper evaluation of cell wall degrading anti-Mtb enzymes. We assessed growth-inhibition by enzymes (recombinant mycobacteriophage mycolic acid esterase (LysB), fungal α-amylase and human and chicken egg white lysozymes) and combinations thereof, in presence or absence of biopharmaceutically acceptable surfactant. Results Our biosafety level-2 assay identified both LysB and lysozymes as potent Mtb-inhibitors, but only in presence of surfactant. Moreover, most potent disruption of the mycolic acid hydrophobic barrier was obtained by the highly synergistic combination of LysB, α-amylase and polysorbate 80. Conclusions Synergistically acting cell wall degrading enzymes are potently inhibiting Mtb – which sets the scene for the design of specifically tailored antimycobacterial (fusion) enzymes. Airway delivery of protein therapeutics has already been established and should be studied in animal models for active TB.

EFFICIENCY OF MULTI-LEVEL ROTARY THERMAL STERILIZATION OF PEAR COMPOTE IN A CONTAINER SKO 1-82-1000 INOPEN-TYPE APPARATUSES WITH THE USE OF LIQUID HIGH-TEMPERATURE HEAT TRANSFER AGENTS

Разработан новый режим многоуровневой стерилизации компота из груш в стеклотаре СКО 1-82-1000 с использованием жидких высокотемпературных теплоносителей, сущность которого заключается в том, что ступенчатый нагрев осуществляется последовательно в воде и растворе диметилсульфоксида с последующим ступенчатым охлаждением в воде с перепадом температур до 20–25°С. Впервые при разработке новых режимов стерилизации введен коэффициент промышленной стерильности Пст, определяемый отношением фактического значения стерилизующего эффекта разработанного режима к нормативному, обеспечивающему промышленную стерильность продукции. Для разработанного стерилизационного режима коэффициент промышленной стерильности с учетом нормативного значения стерилизующего эффекта для компотов, равного 150–200 усл. мин, составляет для пристеночного слоя Пст = 220/200 = 1,1; для центрального слоя Пст = 207/200 = 1,03. Оба значения коэффициента промышленной стерильности приближаются к единице, что говорит об отсутствии перегрева отдельных слоев продукта, характерного для традиционных стерилизационных режимов. Многоуровневый стерилизационный режим способствует снижению длительности термообработки, превышающей 60 мин, при обеспечении требуемого уровня безопасности продукции. A new method of multi-level sterilization of compote from pears in glass containers SKO 1-82-1000 with the use of liquid high-temperature heat transfer agents, the essence of which is that the step heating is carried out sequentially in water and a solution of dimethyl sulfoxide, followed by step cooling in water with a temperature difference of up to 20–25°C. For the first time in the development of new sterilization regimes, the coefficient of industrial sterility was introduced, which is determined by the ratio of the actual value of the sterilizing effect of the developed regime to the standard one that ensures industrial sterility of products. For the developed sterilization mode, the coefficient of industrial sterility, taking into account the standard value of the sterilizing effect for compotes, equal to 150–200 conditional minutes, is for the wall layer Pst = 220/200 = 1,1; for the central layer Pst = 207/200 = 1,03. Both values of the industrial sterility coefficient approach one, which indicates the absence of overheating of individual layers of the product, which is typical for traditional sterilization modes. Multi-level sterilization mode helps to reduce the duration of heat treatment, exceeding 60 minutes, while ensuring the required level of product safety.

P411 Baseline Hypertrophy of the Submucosa at intestinal ultrasound predicts Failure of Treatment in patients with ulcerative colitis

Background Submucosal fibrosis in ulcerative colitis (UC) has been associated with disease severity in colectomy specimens. As intestinal ultrasound (IUS) visualizes all individual wall layers, we aimed to evaluate baseline IUS features to determine endoscopic response and investigate changes in wall layers during anti-inflammatory treatment in patients with UC Methods Moderate-severe UC patients (endoscopic Mayo score (EMS)≥2) extending beyond the rectum starting treatment were included. Simple Clinical Colitis Activity Index (SCCAI), fecal calprotectin (FCP), IUS and endoscopy were performed at baseline and at follow-up between week 8 and 26. BWT, individual wall layer thickness (WT) (mucosa (MC), submucosa (SM) and muscularis propria (MP)) and ratios among layers, Colour Doppler Signal, loss of haustrations, loss of stratification and hyperechogenicity of the submucosa (HoS) (Figure 1) were scored for the sigmoid colon (SC). EMS was assessed for the SC: endoscopic remission (ER) was defined as EMS=0 and endoscopic improvement (EI) as EMS≤1. For statistical analysis a paired t-test and X2-test were used. Results 49 patients were included of whom 61% failed ≥1 biological. 59% started tofacitinib and 41% started a biological. At follow-up, 30% and 49% reached ER and EI, respectively. BWT decreased significantly when ER (2.32 ± 1.63 mm vs 1.00 ± 1.98 mm, p=0.034) or EI (2.53 ± 1.66 mm vs 0.30 ± 1.58 mm, p<0.0001) was reached. In patients with ER and EI, the SM thickness showed significantly more pronounced decrease compared to the other wall layers (Table 1 and Figure 2). Baseline presence of HoS (29% of patients) predicted failure of treatment (ER: OR: 0.10, 95% CI: 0.01-0.87, p=0.014, EI: OR: 0.16, 95% CI: 0.04-0.65, p=0.008,). Furthermore, when HoS was present, SCCAI (7.33 ± 3.62 vs 9.75 ± 3.23, p=0.023) and FCP (1249 ± 903 µg/g vs 2494 ± 2277 µg/g, p=0.008) were significantly lower at baseline. Also, patients with HoS more frequently failed one (OR: 4.44, 95% CI: 1.08-18.32, p=0.03) or multiple biologicals (OR: 5.63, 95% CI: 1.54-20.52, p=0.009). However, disease duration (p=0.950) or age at onset (p=0.853) did not differ between groups. Conclusion This is the first study showing that HoS on IUS is a predictor of endoscopic non-response to biologicals and tofacitinib in patients with UC. Additionally, changes in SM layer thickness is the most important component of the total bowel wall when evaluating mucosal healing on IUS.

435 A Prospective Study of Post-operative Surgical Site Infection

Introduction Organ specific surgical site infections are those that involve any part of the anatomy other than the incised body wall layer opened or manipulated during an operation. The proper understanding of bacteriology and mode of infections has surely reduced the incidence of wound infection, but it is not totally controlled. Method A total of 582 consecutive patient undergoing major and minor surgeries between March 2010 and October 2011 were included in the study. Detail history, physical examination, laboratory and radiological investigation according to Performa with special reference to any factor that could lead to postoperative infection – Age, sex, socioeconomic status, nutrition was recorded. Initial assessment of intra operative findings divided these cases into clean, clean contaminated, contaminated and dirty SSI. Result A total of 582 patients out of these, 100 have SSI, SSI rate in our hospital was found to be 17.18% including all classes of wounds. Coagulase positive staphylococci were responsible for a majority of SSIs and mixed infections were quite common. The other microorganism responsible for SSIs were E.coli, Coagulase negative staphylococci, Pseudomonas and Proteus etc. Conclusions The data from our study suggests a need to control modifiable risk factor responsible for development of SSI.