3D-Printed Mortars with Combined Steel and Polypropylene Fibers

Fibers of various origins are of great importance for the manufacture of new generation cement composites. The use of modified composite binders allows these highly efficient building materials to be used for 3D-printing of structures for various functional purposes. In this article, changes in building codes are proposed, in particular, the concept of the rheological technological index (RTI) mixtures is introduced, the hardware and method for determining which will reproduce the key features of real processes. An instrument was developed to determine a RTI value. The mixes based on composite binders and combined steel and polypropylene fibers were created. The optimally designed composition made it possible to obtain composites with a compressive strength of 93 MPa and a tensile strength of 11 MPa. At the same time, improved durability characteristics were achieved, such as water absorption of 2.5% and the F300 frost resistance grade. The obtained fine-grained fiber-reinforced concrete composite is characterized by high adhesion strength of the fiber with the cement paste. The microstructure of the developed composite, and especially the interfacial transition zone, has a denser structure compared to traditional concrete. The obtained materials, due to their high strength characteristics due to the use of a composite binder and combined fiber, can be recommended for use in high-rise construction.

Implementation of Technical and Technological Progress in Dairy Production

The involvement of people and technical devices is a characteristic feature of technological processes in agriculture. Human access to modernized and more efficient technical equipment determines the differentiation of the proportions of the contributions of human labor and technical equipment to the implementation of production technology on farms. Taking into account the data on manual and machine work inputs, the methodology of determining the technological index level (TL) was presented. The aim of the present study was to present the scope of use of the technological index level to assess the effects of technological progress in the dairy production system, with particular emphasis on cow milking. For the value range of the technological index level (0–100%), changes in the milkman’s work efficiency were presented based on research carried out on farms equipped with milking equipment at different levels of technical advancement. Moreover, the course of changes in electricity and water consumption per liter of milk was determined in association with the technological index level. The issue of simultaneous implementation of various forms of progress was developed based on the example of milking cows with a milking robot. Five categories (ranges) of cows’ milk yield were distinguished and compared with the current yields of cows in the European Union. On this basis, a discussion was initiated on the factors that facilitate and limit the implementation of technical and technological progress in dairy production.

Initial production and fruit quality of scion-rootstock combinations in orange trees in Amazonas

The cultivation of orange trees in Amazonas, Brazil relies predominantly on grafted plants combining ‘Pera’ scion and ‘Rangpur’ lime rootstock. Alternative rootstocks better adapted to the conditions of the region have not been investigated. Therefore, the objective of this research was to test seven rootstocks for the production of high-quality oranges under the typical conditions of the Amazon. Citrus production was evaluated from May to August between 2017 and 2019, based on the variables of cumulative yield, yield efficiency, and crop-yield index over the study period. The fruit physicochemical quality was evaluated by quantification of total soluble solids, total titratable acidity, ratio, juice percentage, and technological index. ‘Indio,’ ‘BRS Bravo’, and ‘Riverside’ genotypes combined with ‘Pera’/CNPMF scion had the highest yield and good fruit quality. They are potentially the most suitable combinations to grow sweet oranges in the Amazon.

The Method of Creating and Measuring the Printability of Fine-Grained Concrete

One of the factors hindering the normal development of additive construction technologies is the lack of reasonable methods for evaluating the suitability of mixtures for printing. This makes it almost impossible to compare remotely the compositions of different developers, makes it difficult to develop equipment and regulatory documentation, without which it is impossible to complete industrial production. The paper considers the feasibility of introducing the concept of “printability” of compositions and “rheological technological index of mixtures” as a numerical indicator for its evaluation. The design of the device for determining the rheological technological index is described. The developed device has a low cost of production, is linked to standard equipment of construction laboratories and emulates the main types of effects on the mixture during the extrusion process. The effective method for ensuring the printability of fine-grained concretes is considered based on the joint use of traditional plasticizing additives with entrained agents – foaming agents for cellular concretes. The effect of these additives is realized at different scale levels (micro-and mesolevels (cement paste) – traditional superplasticizers; macro-level (fine aggregate) - entrained agents), which together provides high rheological technological indices and effectiveness of mixtures with increased amounts of sand, low W/C ratios and small dosages of these additives. The use of additional mineral or organic rheology modifiers that increase the cost of the mixture is not required in this case. The structural features and basic properties of the developed composites are studied, allowing making comparisons with the solutions of other developers, assessing the prospects of the proposed method of ensuring printability, and outlining directions for its further improvement.

CHANGE OF CONSUMER PROPERTIES OF PORK, DEPENDING ON THE FEED DIET

Изучено влияние кормового витаминно-минерального концентрата (КВМК) «Тетра+» на потребительские свойства свинины, в том числе пищевую ценность, технологические и кулинарные свойства. Объект исследования – свинина второй категории от отобранного из поголовья опытной и контрольной групп молодняка свиней массой 100 кг, находившихся на откорме 140 дней. Поросята контрольной группы, начиная от подсосного периода, получали основной рацион (ОР); поросята опытной группы получали КВМК «Тетра+» в количестве 1% в дополнение к ОР. Охлажденное мясо от молодняка свиней обоего пола контрольной и опытной групп оценивали по органолептическим показателям спустя 48 ч после убоя. Определено, что образцы свинины, полученной от опытной группы (ОГ) животных, содержат на 4,1% больше белка по сравнению с образцами свинины от контрольной группы (КГ), при этом доля влаги и жира в образцах мяса от ОГ ниже на 3,08 и 1,10% соответственно. Содержание фосфолипидов в свинине от ОГ на 0,32% выше, чем в свинине от КГ. Установлено, что влагосвязывающая способность мышечной ткани свинины от ОГ на 3,11% выше аналогичного показателя КГ; потери при тепловой обработке свинины от ОГ на 2,17% соответственно ниже. Кулинарно-технологический показатель мышечной ткани реберного отруба свинины от ОГ выше на 0,15 единиц. Суммарная дегустационная оценка образцов вареной свинины опытной и контрольной групп составила 44,3 и 39,7 баллов соответственно. The influence of feed vitamin and mineral concentrate (FV&MC) «Tetra+» on consumer properties of pork, including nutritional value, technological and culinary properties, was studied. The object of research is the second category of pork from the experimental and control groups of young pigs weighing 100 kg that were fattened for 140 days. Control group pigs received the main diet; experimental group received FV&MC «Tetra+» in an amount of 1% in addition to the main diet. Chilled meat from young pigs of both sexes of the control and experimental groups was evaluated by organoleptic parameters 48 hours after slaughter. It was determined that samples of pork obtained from the experimental group of animals contain 4,1% more protein compared to samples of pork from the control group, while the proportion of moisture and fat in meat samples from the experimental group of animals is lower by 3,08 and 1,10%, respectively. The content of phospholipids in pork from the experimental group is 0,32% higher than in pork from the control group. It was found that the moisture-binding capacity of the muscle tissue of pork from the experimental group is 3,11% higher than the same indicator of pork from the control group; losses during heat treatment of pork from the experimental group are 2,17% lower. Culinary and technological index of muscle tissue of the rib cut of pork from the experimental group is higher by 0,15. The total tasting score of cooked pork in the experimental and control groups was 44,3 and 39,7 points, respectively.

Physical and Chemical Characterization of Fruits of Different Umbu (Spondias tuberosa) Accesses

The umbuzeiro is a native Brazilian semi-arid plant with great agroindustrial potential. The characterization of the fruit, as well as the development or improvement of technologies for value aggregation are fundamental for its conservation, dissemination and culinary expansion. The objective was to characterize physically and chemically fruits of umbu and to define the access with greater commercial potential. A completely randomized design was used, with 10 replications, in a total of 4 accessions of umbuzeiro. The fruits were selected prioritizing uniformity of fruit size and maturation stage. Fruit peel color was analyzed; diameter and length; mass of the fruit, the bark, the pulp and the seed; firmness of the fruit, soluble solids contents; pH; titratable acidity and solids/acidity ratio. The values of the pulp yield and the technological index were determined. Significance was verified for all variables, except for soluble solids and pH. The average value of the titratable acidity was 1.3 mg of citric acid 100 mL-1 of juice. The diameter of the fruits varied between 4.0 and 4.5 cm. Fruit mass varied from 33.00 to 43.62 g and access to EPAMIG-C06 was the heaviest. The accesses EPAMIG-C06 and EPAMIG-C18 presented the highest technological index. Based on the results, it was concluded that the accesses present potential to the pulp industry due to the size and characteristics of the fruits. The umbu accesses under study presented small variation for solubility and pH. For in natura consumption and/or processing, the access EPAMIG-C06 stands out due to attributes of commercial interest.

Performance of 'Valência' sweet orange grafted onto rootstocks in the state of Acre, Brazil

The objective of this work was to select rootstocks, based on the agronomic characters and fruit quality of the 'Valência' orange tree. The evaluated rootstocks were: the 'Cleópatra' mandarin; the TSKFL x CTTR-013, LVK x LCR-038, TSKC x CTQT 1439-004, LVK x LVA-009, TSK x TRENG-256 ('Indio' citrandarin) hybrid genotypes; the 'Santa Cruz' Rangpur lime; and the TSKFL x CTC-25-002, and TSKC x CTSW-038 hybrids. The experiment was installed in 2010 and evaluated from 2013 to 2017. The parameters plant height, canopy volume, yield efficiency, scion:rootstock ratio, survival percentage, and drought tolerance were evaluated in 2017. The yield average of five harvests was estimated, as well as the annual production per plant and the accumulated production. The analyzed fruit traits were: mass, diameter, peel length and thickness, juice yield, soluble solids, acidity, and technological index. 'Valência' shows a lower plant height and canopy volume, besides a higher yield efficiency, when grafted on TSKC x CTSW-038 than on the other rootstocks. LVK x LCR-038, TSKC x CTQT 1439-004, 'Indio' citrandarin, and 'Santa Cruz' Rangpur lime increase the production of the 'Valência' orange. LVK x LCR-038 and the 'Indio' citrandarin induce the scion to produce a better quality fruit.

Plant growth, yield and fruit quality of ‘Piemonte’ tangor grafted onto 14 rootstocks on the northern coast of the state of Bahia, Brazil

In the state of Bahia, Brazil, citrus production is mainly on the Northern Coast region, with major cultivation of ‘Pera’ sweet orange grafted onto ‘Rangpur’ lime. The production of mandarins and mandarin-like fruits is very low in spite of the increasing regional consumption. Varieties that are adapted to tropical sub humid conditions should be evaluated on different rootstocks for cultivation recommendation. This study assessed the performance of ‘Piemonte’ tangor over 14 rootstocks in Rio Real, BA. Planting was performed in 2006 on a cohesive yellow argisol, at 6.0 m x 4.0 m spacing and with no irrigation. Plant growth, production, and physicochemical attributes of fruits in 2010-2014 were assessed, in addition to tree survival and drought tolerance based on leafroll. At nine years of age, rootstocks that induced greater cumulative production of ‘Piemonte’ were ‘Riverside’ and ‘Indio’ citrandarins, ‘Santa Cruz Rangpur’ lime, and ‘Cleopatra’, ‘Sunki Tropical’ and ‘Sunki Maravilha’ mandarins. Although four hybrid rootstocks were semidwarfing, their mean efficiency was equivalent to the other rootstocks (˜ 5.5 kg m-3), resulting in the lowest production. Drought tolerance and tree survival were similar among rootstocks with minimal loss, except for TSKFL x CTSW - 049 hybrid with only 33.33% of survival. ‘Piemonte’ tangor produced fruits with general good quality under the evaluated conditions, but only peel thickness and technological index (TI) were influenced by rootstocks, with the lowest TI averages recorded for fruits harvested from scions grafted onto TSKC x (LCR x TR) - 001 and ‘Volkamer’ lemon.