Uniform Product Research Articles

Continuous flow synthesis of plasmonic gold patches and nearly-complete nanoshells on polystyrene core particles

We describe the development of a T-mixer based continuous flow process for the coating of 86–500 nm diameter spherical polystyrene particles with thin gold patches by heterogeneous nucleation and growth. After establishing a suitable flow rate for good mixing and sufficiently uniform product morphology we systematically investigate the main reaction parameters. This reveals a considerable tunability of the patch morphology and, by virtue of the localized surface plasmon resonance of gold, the optical properties of the product dispersions. In order to further widen the range of nanostructures accessible by our process, a second T-mixer was added. This introduced new gold precursor, leading to further growth of the patches that were formed after the first mixer. By this approach, nearly-complete gold nanoshells could be produced in high yield on both small and large core particles, without the unwanted production of free-standing gold nanoparticles. Due to the pronounced optical properties of nearly-complete gold nanoshells on small core particles, we could estimate from electrodynamic simulations the equivalent shell thickness to be as low as 8.6 nm. This is significantly thinner than can be routinely achieved using the standard seeded growth approach to synthesise gold nanoshells. Our results are therefore highly promising for the gram-scale synthesis of plasmon resonant nanostructures with designed optical properties.

A machine learning approach for clinker quality prediction and nonlinear model predictive control design for a rotary cement kiln

AbstractCement manufacturing is energy‐intensive (5Gj/t) and comprises a significant portion of the energy footprint of concrete systems. Incorporating modern monitoring, simulation and control systems will allow lower energy use, lower environmental impact, and lower costs of this widely used construction material. One of the goals of the CESMII roadmap project on the Smart Manufacturing of Cement included developing an analytical process model for clinker quality that includes the chemistry of the kiln feed and accounts for critical process variables. This predictive model will be used in nonlinear model predictive control system designed to significantly reduce process energy use while maintaining or improving product quality. In the cement manufacturing plant used in this study, the kiln feed (meal) is tested every 12 h and used to estimate the mineral composition of the cement kiln output (clinker) using the stoichiometry‐based Bogue's model and the expertise of the plant operators. During kiln operation, kiln output (clinker) is sampled and tested every 2 h to measure its chemical and mineral composition. The predicted and measured values of the clinker composition are used by the plant operators to adjust the kiln input stream and the production process characteristics to maintain stable operation and uniform product quality. However, the time delay between prediction and testing, along with inaccuracies inherent in the Bogue's model have made any process changes designed to minimize energy use problematic, especially in‐light of potential clinker quality issues that process changes often pose. A new analytical model that integrates quality information and process operation information has been developed from data collected from 2 years of production from an operating cement facility. To make the model fuel‐type‐independent, consumed heat energy was computed in the model instead of fuel type and amount. A Feedforward Network was trained and tailored from collected data. Many data‐based simulations were conducted to quantitatively evaluate the proposed model and the 5‐fold cross‐validation procedure was used to test the models. The resulting predictive model was shown to have a low root mean square error (MSE) with respect to the estimated clinker mineral composition compared to that using the industry standard “Bogue’ model”. The end goal of this work was to develop a single machine learning tool that allows the use of quality control data and process control variables to improve energy efficiency of the process in a continuous fashion. The proposed nonlinear model predictive control system (NMPC) can generate predicted kiln production characteristics based on manipulated variables in manner that accurately follows the target product quality values. Simulation results also show that the proposed model produced accurate predictions of kiln outputs that fell within the required constraints, while manipulating control variables within typical operational ranges.

Alginate encapsulation of micro-cuttings in endangered Satureja khuzistanica species: a promising method for obtaining genetically stable plants with high rosmarinic acid content

Synthetic seed technology is a suitable approach for the rapid, and uniform mass production of Satureja khuzistanica Jamzad, a valuable medicinal plant of the Lamiaceae family. In this study, the encapsulation of micro-cuttings of S. khuzistanica using sodium alginate (SA) was investigated. In order to determine the best conditions for encapsulation, different concentrations of SA and CaCl2·2H2O, different types of explants and matrix culture media, different types and concentrations of plant growth regulators, and different cold storage conditions of synthetic seeds were tested. Also, the genetic stability of regenerated plants from synthetic seeds using the inter simple sequence repeat (ISSR) molecular marker as well as the content of rosmarinic acid in synthetic seed-derived plants were evaluated. The use of 3% SA and 100 mM CaCl2·2H2O was found to be optimal for gel complexation. Encapsulation of nodal segments with 1/2 Murashige and Skoog (MS) medium containing 2.5 µM 6-Benzylaminopurine resulted in the highest regrowth percentage (72.22%) and regrowth rate (0.173). Pre-culture of nodal segments in 1/2 MS medium containing 5 µM indole-3-butyric acid (IBA) and 0.2% activated charcoal for 10 days and the use of 2.5 µM IBA in the rooting medium resulted in the highest rooting percentage (88.88%) in synthetic seed-derived plants. The highest regrowth percentage (61.11%) and regrowth rate (0.173) of synthetic seeds were obtained using 2.0 µM thidiazuron (TDZ) in MS liquid medium. The placement of germinated seeds on the coco peat substrate resulted in the highest conversion rate (61.11%) of synthetic seeds. Also, storage of encapsulated nodal segments at 4 °C in MS culture medium, compared to cold storage without using MS medium, resulted in better regrowth of synthetic seeds. The highest regrowth percentage (44.44%) and regrowth rate (0.092) for cold-stored synthetic seeds occurred after 2 weeks. The genetic stability testing by ISSR molecular marker showed that synthetic seed-derived plantlets were genetically similar to their mother plants. Also, encapsulated nodal segments and shoot tip-derived plants significantly enhanced the rosmarinic acid content up to 7.77 times that of the natural seed-derived plants. Genetic restoration programs, short-term storage, and germplasm distribution in S. khuzistanica plants could all benefit from the encapsulation regeneration strategy reported here.

Production trials of in-pond raceway system growing stocker and foodsize hybrid Catfish plus Nile tilapia

In Pond Raceway systems (IPRS) consist of floating or fixed floor rectangular raceways (RW) assembled or placed into existing earthen ponds. This case study evaluated the performance and economics of producing foodsize hybrid Catfish and stocker sized fingerlings in IPRS and Nile tilapia grown in cages, placed into four 0.4 ha ponds. Growout raceways in ponds 1 and 2 were 63 m3, and 45 m3 in ponds 3 and 4. Each pond had one (14 m3) stocker unit raceway plus a 36 m3 Nile tilapia cage placed into ponds 2 and 4. Each pond had 5.0 HP of aeration that maintained adequate DO levels. Catfish were fed a 32% CP commercial diet twice a day; Nile tilapia were allowed only to graze the phytoplankton flow generated by the growout and stocker IPRS units. The combined production from growout (186 days) and stocker (142 days) resulted in 19,712 kg/ha in pond 1, 19,302 kg/ha in pond 2, 19,426 kg/ha in pond 3, and 16,555 kg/ha in pond 4. The same number of Nile tilapia were stocked into the two cages and resulted in yields of 2167 kg/ha (pond 2) and 2160 kg/ha (pond 4); when combined with catfish production resulted in total gross production of 21,469 kg/ha in pond 2 and 18,715 kg/ha in pond 4. Foodsize average harvest weights ranged from 670 to 894 g, with survival rates ranging from 86 to 98%, and having weight gain per day (WGD) of 1.74 to 3.22 g/day. Raceway stocker unit achieved harvest weights ranging from 173 g to 186 g, with survival rates ranging from 75 to 90% and having WGD from 1.02 to 1.37 g. In general, efficient FCRs were achieved in all growout and stocker hybrid Catfish IPRS units. Hybrid Catfish raised in IPRS demonstrated excellent fish inventory control, promoted uniform hybrid Catfish production, with 90 to 95% of the foodfish harvested in the preferred premium size range. Production strategies for inclusion of co-cultured Nile tilapia along with the catfish IPRS systems were achieved with little investment and operating costs, resulting in overall positive net returns. Ponds housing IPRS catfish units plus a Nile tilapia cage had reduced investment payback periods, increased net present value and higher internal rates of return.

High-Order Groove-Shape Curve Roll Design for Aluminum Alloy 7075 Wire Rolling

A Bézier curve groove-shape roll design method was proposed and compared to round-oval-round designs for the wire rolling process. CAE simulations were adopted to predict the rolling forces and torques required for the rolling process. The rolling torque required for the case of 28% vertical compression rate is 73% higher than the case of 12% compression rate. The curve fittings of the rolling torque and the compression force with respect to the compression rate were obtained with very high R-square values (0.99 and 0.98) in the first rolling pass. The rolling force required for the Bézier curve groove-shape design is no different compared to the oval design with the same compression rate, but the rolling torque requirement for the next rolling station is 6% less than the oval groove design. Furthermore, the equivalent strain distribution on the cross section of the product was uniform, and no fin flash defects occurred. The proposed Bézier curve groove-shape is a better design from the viewpoint of uniform product mechanical property requirement, and a larger compression rate per pass could be achieved.

Timber structures made of naturally curved oak wood: prototypes and processes

Highly optimised processing workflows characterise today’s wood industry. The gained efficiency is mainly directed towards making standardised linear materials that fulfil the market’s expectation of a continuous flow of identical products with certain constant specifications. The research presented here seeks to question these limitations and provide another approach to the use of wood in construction. The study involves complex geometry handling, architectural design, and material and structural considerations. Trees absorb CO2 during growth, and as a construction material, wood can function as CO2 storage, thereby reducing the levels in the atmosphere during the lifetime of the building—and even longer if the building components can be reused. We have seen a significant rise in wood construction over the past few years. This is partly due to growing climate awareness and the increased availability of engineered wood products (EWP). EWPs are reliant on uniform tree production. With growing interest in using wood for construction, an increase in plantation forests is predicted, leading to a lack of biodiversity in the affected areas. The consideration for the general climate expressed through the increased use of wood as a building material may thus appear to be in contrast to the efforts to improve biodiversity. This research seeks to provide an alternative route where non-uniform wood, usually used as firewood, can be used as a construction material. The project demonstrates possibilities that emerge from engaging with the wood as a specific occurrence of a biological entity rather than a standardised material. While historical precedents inspire the research, the project has been developed using digital tools, such as laser scanning, algorithmic design and robotic fabrication. We have developed a unique design-to-production workflow that uses curved natural wood in its original form to enable curved architectural designs. The workflow thereby links the inherent properties of the wood to a distinct mode of expression. The wood is retrieved from a sawmill that collects discarded tree trunks from local forests. The sawlogs are registered with a 3D scanner, and a customised parametric method is used to handle the geometric information and establish a database of the irregular saw logs. A custom-made algorithmic design tool identifies where the sawlogs fit best in a predefined construction design based on the database. Machining data is directly extracted for the subsequent robotic processing. The irregular shape of the material suggests a discrete analysis of the structural properties of each component. A series of destructive physical tests are carried out to indicate the capacity of the structural system and the joint solution. To demonstrate the viability of the workflow, study challenges in controlling tolerances and humidity, and develop an assembly strategy, we have produced a construction prototype of 15 members in the size of 3 m in width and 4 m in height.

Attenuation of voltage sags effects and dynamic performance improvement of a multi-motor system

In many continuous manufacturing processes such as paper, textile, winding and plastic extrusion, electric drives are frequently required to work in synchronization, often with high tolerances to ensure uniform product quality and avoid failure of the product. In a multi-motor system (MMS), voltage dips are the most common cause of the motor stoppage, and the transient loss of synchronism between motors can result in a complete system shutdown. This paper proposes a multi-motor system controlled by a Backstepping strategy to ensure servo-control and synchronization of induction motors. This technique includes indirect rotor field-oriented control (IRFOC), linear speed control, and mechanical tension control, of induction motors. Investigations of symmetrical voltage sag effects on speed, torque, and mechanical tension are also carried out. Simulation results obtained using Matlab®/SimulinkTM/SimPowerSystems® are presented to demonstrate the efficiency of the proposed control strategy.

Variational methods for contracting projected entangled-pair states

The norms or expectation values of infinite projected entangled-pair states (PEPS) cannot be computed exactly, and approximation algorithms have to be applied. In the last years, many efficient algorithms have been devised -- the corner transfer matrix renormalization group (CTMRG) and variational uniform matrix product state (VUMPS) algorithm are the most common -- but it remains unclear whether they always lead to the same results. In this paper, we identify a subclass of PEPS for which we can reformulate the contraction as a variational problem that is algorithm independent. We use this variational feature to assess and compare the accuracy of CTMRG and VUMPS contractions. Moreover, we devise a new variational contraction scheme, which we can extend to compute general N-point correlation functions.

Key environmental and production factors for understanding variation in switchgrass chemical attributes

AbstractSwitchgrass (Panicum virgatum L.) is a promising feedstock for bioenergy and bioproducts; however, its inherent variability in chemical attributes creates challenges for uniform conversion efficiencies and product quality. It is necessary to understand the range of variation and factors (i.e., field management, environmental) influencing chemical attributes for process improvement and risk assessment. The objectives of this study were to (1) examine the impact of nitrogen fertilizer application rate, year, and location on switchgrass chemical attributes, (2) examine the relationships among chemical attributes, weather and soil data, and (3) develop models to predict chemical attributes using environmental factors. Switchgrass samples from a field study spanning four locations including upland cultivars, one location including a lowland cultivar, and between three and six harvest years were assessed for glucan, xylan, lignin, volatiles, carbon, nitrogen, and ash concentrations. Using variance estimation, location/cultivar, nitrogen application rate, and year explained 65%–96% of the variation for switchgrass chemical attributes. Location/cultivar × year interaction was a significant factor for all chemical attributes indicating environmental‐based influences. Nitrogen rate was less influential. Production variables and environmental conditions occurring during the switchgrass field trials were used to successfully predict chemical attributes using linear regression models. Upland switchgrass results highlight the complexity in plant responses to growing conditions because all production and environmental variables had strong relationships with one or more chemical attributes. Lowland switchgrass was limited to observations of year‐to‐year environmental variability and nitrogen application rate. All explanatory variable categories were important for lowland switchgrass models but stand age and precipitation relationships were particularly strong. The relationships found in this study can be used to understand spatial and temporal variation in switchgrass chemical attributes. The ability to predict chemical attributes critical for conversion processes in a geospatial/temporal manner would provide state‐of‐the‐art knowledge for risk assessment in the bioenergy and bioproducts industry.

Combining Functional Prototyping of 3D Printed Reactors with a Modular Reactor Setup for Continuous Emulsion Polymerization

AbstractThe potential for fast and specific process optimization by functional prototyping with 3D printed reactors was shown for a known continuous emulsion polymerization in a modular setup. Three tubular reactors, two with static mixing elements and a continuously stirred tank reactor (CSTR) were printed from polylactic acid. Thermal imaging of the reactors allows to map the basically adiabatic progress of the redox‐started radical polymerization in a space‐resolved way. The application of static mixing elements led to a higher conversion stability and a more uniform product, as expected for a better mass transfer. Polymerization in combinations of CSTR and a tubular reactor showed further improvements of process stability and product uniformity in terms of particle size and mol masses.

Optimization studies on mixing of curd and ingredients during Lassi (StirredCurd) manufacturing

Consumption of the fermented milk is on the rise due to its therapeutic benefits to human health. Several processes and technologies evolved to further enrich the fermented foods. In the present study, an Indian fermented milk product Lassi (sweet stirred curd) was selected for the experimental trials and optimized for the different process conditions. Lassi was prepared by adding sugar and water in curd and mixing them in the prefabricated mixing vessel. Three different impellers were tested in the preparation of Lassi. Two independent factors, namely off-bottom clearance (OBC) and impeller speed (IS) were selected to optimize the process conditions to yield a uniform good quality product. The quality of the finished product was assessed by sensorial and rheological attributes. Performance of the impeller was estimated by evaluating the mixing time, mixing index and power consumption. Three levels of OBC (3, 6, 9 cm) and IS (300, 400, 500 rpm) respectively were selected. Experiments were designed as per response surface methodology and accordingly trials were conducted. Constraints were optimized by setting up the goal for each of them. Based upon the solutions provided by the software, the product was prepared keeping the impeller positioned at 4.8 cm OBC and rotational speed of 389 rpm. The prepared product was validated against the experimental values and found no significant difference between theoretical and experimental values. Results indicated that the multivane churn impeller was found to be suitable for the preparation of good quality lassi. Mixing time and power consumption were optimized at 160±17.32 and 34.21±0.70, respectively. Overall acceptability of the product was 8.16±0.153 on 9-point hedonic scale. It can be concluded that the developed unit and impeller was able to deliver a uniform quality product with minimum mixing time and power consumption.

A novel approach used to study the corrosion susceptibility of metallic materials at a dynamic seawater/air interface

A novel device is constructed to study the localized corrosion susceptibility of 2024 aluminum alloy at a dynamic seawater/air interface. Corrosion in three distinct regions are identified: full immersion region, seawater/air interfacial region (alternant wet/dry region), and atmosphere region. The corrosion process in the interfacial region over time was studied by EIS and the corrosion product was characterized by SEM. Experimental results revealed that, a layer of intense and uniform corrosion product was formed on the seawater/air interfacial region, due to the oxygen enrichment in that region. Pitting corrosion was more severe in the full immersion region than that in the seawater/air interface, as verified by a lower charge transfer resistance and more severe pitting corrosion and intergranular corrosion extent.

Ground-state separability and criticality in interacting many-particle systems

We analyze exact ground state (GS) separability in general $N$ particle systems with two-site couplings. General necessary and sufficient conditions for full separability, in the form of one and two-site eigenvalue equations, are first derived. The formalism is then applied to a class of $SU(n)$-type interacting systems, where each constituent has access to $n$ local levels, and where the total number parity of each level is preserved. Explicit factorization conditions for parity-breaking GS's are obtained, which generalize those for $XYZ$ spin systems and correspond to a fundamental GS multilevel parity transition where the lowest $2^{n-1}$ energy levels cross. We also identify a multicritical factorization point with exceptional high degeneracy proportional to $N^{n-1}$, arising when the total occupation number of each level is preserved, in which any uniform product state is an exact GS. Critical entanglement properties (like full range pairwise entanglement) are shown to emerge in the immediate vicinity of factorization. Illustrative examples are provided.

Establishment of highly efficient plant regeneration of Paeonia ostii ‘Fengdan’ through optimization of callus, adventitious shoot, and rooting induction

Tree peony is a famous ornamental plant, while the low propagation rate is the main hurdles hindering the industry development. Till now, the highly efficient regeneration system for tree peony is not established. In this study, using Paeonia ostii ‘Fengdan’ mature embryos, the effects of variations in inoculation method, initiating culture, adventitious shoot induction, rooting media, plant growth regulators (PGRs), and a non-conventional PGR (plant extracts) on regeneration from explants were evaluated. In embryo cultures, embryonic callus induction rate of 1/4 embryos was the highest among those of embryos with other three technical treatments (whole embryos, 1/2 embryos, and pieces of embryos). The woody plant medium (WPM) containing 1.0 mg • L − 1 6-BA, 0.5 mg • L − 1 GA3, 30.0 g • L − 1 sucrose, and 3.0 g • L − 1 phytagel significantly improved shoot induction and multiplication. 3.0 mg • L − 1 plant extracts promoted hypocotyl germination, rooting, and root growth, in direct embryo culture, and a combination of 3.0 mg • L − 1 plant extracts + 2.0 mg • L − 1 IBA + 1.5 mg • L − 1 IAA produced optimal rooting induction rate for multiple shoots in direct embryo culture and indirect somatic embryogenesis. For the three in vitro micropropagation methods, the highest shoot proliferation coefficient (5.4 ± 0.2) was obtained with indirect somatic embryogenesis. Fortunately, the propagation ability of shoots remains high, even when culture propagation was continued for more than two years. Thus, a reliable system for plant regeneration from mature embryos derived from P. ostii ‘Fengdan’ callus and two direct embryo culture systems have been established. The novel regeneration system could facilitate uniform seedling production.

Evaluation of coat color inheritance and production performance for crossbreed from Chinese indigenous Chenghua pig crossbred with Berkshire

ObjectiveThis work was to determine coat inheritance and evaluate production performance for crossbred pigs from Berkshire×Chenghua (BC) compared with Chinese indigenous Chenghua (CH) pigs.MethodsThe coat color phenotypes were recorded for more than 16,000 pigs, and the genotypes of melanocortin 1 receptor (MCIR) gene were identified by sequencing. The reproductive performance of 927 crossbred BC F4 gilts and 320 purebred CH gilts was recorded. Sixty pigs of each breed were randomly selected at approximately 60 days of age to determine growth performance during fattening period, which lasted for 150 days for BC pigs and 240 days for CH pigs. At the end of the fattening period, 30 pigs of each breed were slaughtered to determine carcass composition and meat quality.ResultsThe coat color of BC pigs exhibits a “dominant black” hereditary pattern, and all piglets derived from boars or sows genotyped ED1ED1 homozygous for MC1R gene showed a uniform black coat phenotype. The BC F4 gilts displayed a good reproductive performance, showing a higher litter and tear size and were heavier at farrowing litter and at weaning litter than the CH gilts, but they reached puberty later than the CH gilts. BC F4 pigs exhibited improved growth and carcass characteristics with a higher average daily live weight gain, lower feed-to-gain ratio, and higher carcass lean meat rate than CH pigs. Like CH pigs, BC F4 pigs produced superior meat-quality characteristics, showing ideal pH and meat-color values, high intramuscular fat content and water-holding capacity, and acceptable muscle-fiber parameters. C18:1, C16:0, C18:0, and C18:2 were the main fatty acids in M. longissimus lumborum in the two breeds, and a remarkably high polyunsaturated/saturated fatty acid ratio of ~0.39 was observed in the BC F4 pigs.ConclusionThe BC F4 pigs exhibit a uniform black coat pattern and acceptable total production performance.

Developing a Marketing Strategy to Improve the Market Activities of Agricultural and Processing Enterprises, Using the Policy of “Goodvalley” as an Example

In the national economies of many countries, especially developing ones, agriculture represents a significant share of GDP. The relevance of the issue stated in the study is due to the fact that the marketing strategy of agricultural enterprises is the most important element of their management system, which contributes to the sustainable development of agriculture and provision of the population with better quality food products. The need to increase the competitiveness of agricultural enterprises among similar ones also contributes to the development of agricultural technologies for obtaining high quality and environmentally friendly products. The purpose of this study is to investigate the nature of a modern agricultural company’s marketing strategy. The leading method for investigating this issue is the empirical method, namely examining the practice of marketing strategy in agriculture. As a result of the study, it has been established that a marketing strategy in the agricultural sector should make an enterprise stand out from its competitors through non-price methods. This is primarily due to the peculiarity of agricultural products – they are quite homogeneous, standardised and subject to state regulation not only in terms of safety, but also in terms of conformity with their name. It has been revealed that due to current trends in modern society regarding the need for environmentally friendly production and healthy lifestyles, it is desirable to include these elements in an agricultural company’s marketing strategy. Serious work needs to be done to improve the brand image and the image of the producer. These marketing techniques enable an agricultural company to stand out from its competitors and keep prices and demand at the required level. The results of this marketing strategy make it possible to turn a standardised, uniform product from an agricultural producer into an exclusive, special, high-end product

Pitting corrosion behavior of Cu–P–RE weathering steels

The weathering steels are prone to pitting corrosion in an environment containing chloride ions. The pitting behavior of Cu–P–RE weathering steels and its effect on the corrosion resistance of steels were investigated by multifarious analytical techniques, such as field emission-scanning electron microscopy (FE-SEM), electron probe microanalysis (EPMA), scanning Kelvin probe force microscopy (SKPFM), electrochemical workstation and a series of immersion tests. The results show that the original strip-shaped MnS inclusions and Al2O3 inclusions with sharp angles are modified into the fine spherical rare earth (RE) inclusions with small average size, which are mainly RE oxysulfides after adding appropriate amount of mischmetal (48.9 wt%Ce–42 wt%La–5 wt%Nd–Fe) into the Cu–P weathering steel. In the environment containing Cl–, the pitting corrosion in RE weathering steel is induced by the preferential dissolution of RE inclusions in that the RE inclusions have a more negative potential than steel matrix at the initial corrosion stage. With the increase of corrosion time, the driving force of pitting expansion is weakened as a result of the continuous dissolution of RE inclusions, which makes the pitting tend to propagate horizontally around the RE inclusions. Once the RE inclusions completely dissolve, the open corrosion pits with shallow depth are formed in steel. The dispersed pitting pits with small size and shallow depth induced by RE inclusions are conducive to the formation of uniform and dense corrosion products layer on the steel surface, which reveals that the addition of RE can improve the corrosion resistance of weathering steels.

Mesenchymal stem/stromal cell–based therapies for COVID-19: First iteration of a living systematic review and meta-analysis: MSCs and COVID-19

BackgroundMesenchymal stem/stromal cells (MSCs) and their secreted products are a promising therapy for COVID-19 given their immunomodulatory and tissue repair capabilities. Many small studies were launched at the onset of the pandemic, and repeated meta-analysis is critical to obtain timely and sufficient statistical power to determine efficacy. Methods and FindingsAll English-language published studies identified in our systematic search (up to February 3, 2021) examining the use of MSC-derived products to treat patients with COVID-19 were identified. Risk of bias (RoB) was assessed for all studies. Nine studies were identified (189 patients), four of which were controlled (93 patients). Three of the controlled studies reported on mortality (primary analysis) and were pooled through random-effects meta-analysis. MSCs decreased the risk of death at study endpoint compared with controls (risk ratio, 0.18; 95% confidence interval [CI], 0.04 to 0.74; P = .02; I2 = 0%), although follow-up differed. Among secondary outcomes, interleukin-6 levels were most commonly reported and were decreased compared with controls (standardized mean difference, –0.69; 95% CI, –1.15 to –0.22; P = .004; I2 = 0%) (n = 3 studies). Other outcomes were not reported consistently, and pooled estimates of effect were not performed. Substantial heterogeneity was observed between studies in terms of study design. Adherence to published ISCT criteria for MSC characterization was low. In two of nine studies, RoB analysis revealed a low to moderate risk of bias in controlled studies, and uncontrolled case series were of good (3 studies) or fair (2 studies) quality. ConclusionUse of MSCs to treat COVID-19 appears promising; however, few studies were identified, and potential risk of bias was detected in all studies. More controlled studies that report uniform clinical outcomes and use MSC products that meet standard ISCT criteria should be performed. Future iterations of our systematic search should refine estimates of efficacy and clarify potential adverse effects.

Uniform in diversity: Typological and technological analysis of Bronze Age fine ware from Kakucs-Turján

The ceramic variability of fine ware pottery in Early and Middle Bronze Age Carpathian Basin (2600/2500–1500/1450 BCE) has been used as an argument for the existence of distinct, large-scale communities. The recent technological studies of coarse ware ceramics have shown that different stylistic groups are characterized by uniform technological traits, suggesting that current narratives result from an a priori classification of material culture. To verify whether fine ware ceramics were characterized by similar traits, a sample of 33 vessels from a multi-layered, fortified settlement of Kakucs-Turján (Hungary) was analyzed in terms of vessel forms and underlying production processes. The analyses compared the classical local and non-local provenance objects to determine whether the impressionistic categorization of vessels is supported by discrete parameters. The results indicate that similarly to coarse ware, Early and Middle Bronze Age ceramics in the Carpathian Basin was characterized by uniform production processes suggesting the impact of multi-directional and persisting interaction across the Carpathian Basin.

УСТАНОВЛЕНИЕ ЕДИНЫХ НОРМ ВЫРАБОТКИ И ОПЛАТЫ ТРУДА ГРУЗЧИКОВ В СССР В 1940 Г.

The article deals with the establishment of uniform standards for the production and remuneration of movers in the USSR in 1940. It is indicated that until 1940, due to departmental disunity, there were no uniform production standards in the country, since they were set independently by each department, organization. It happened that in one port for the same work there were different standards of production and remuneration, which led to staff turnover. The beginning of standardization on a national scale was laid with the adoption in 1939 of the technical minimum for work producers and foremen of movers. June 2, 1940 The Economic Council of the Council of People’s Commissars of the USSR adopted Resolution No. 762 «On uniform standards of production and remuneration for loading and unloading operations». In the execution of this order of the highest authorities, on June 16, 1940, Order No. 612 was published by the People’s Commissariat of Procurement of the USSR «On uniform standards of production and remuneration for loading and unloading operations», which became the basis for regulating such types of work throughout the country. Changes to this document were made after the Great Patriotic War, under the influence of wartime conditions.