Production Phase Research Articles

Analysis of standard unit carbon emission and cost assessment of the changing building envelope over material production phase

It is undeniable that the material production stage is crucial to the whole life cycle of structures. This study proposes the window-to-envelope ratio (WER) based on standard units to determine the inherent relationship between changes in door and window areas and carbon emissions, presuming six distinct types of engineering practices for various buildings are selected. It was concluded that larger door and window areas would result in more embodied carbon emissions. Additionally, as the size of windows and doors increases, the costs and embodied carbon of prefabricated and cast-in-place construction become more comparable. According to the analysis, when the building scale is larger and the door and window opening area is also larger, prefabrication has more potential for saving carbon than cast-in-place building, but with a cost of approximately 10–20% higher. Considering the perspective of consumers, producers, and markets, this study revealed a costing assessment methodology based on standard units for prefabricated structures. In this methodology, producers choose and create various residential layouts based on the distinctive requirements of consumers, while tracking the trends in carbon emissions and production costs. This assessment method tries to create a favorable atmosphere for moral market activity and offers an acceptable solution for the trade-off between environmental and economic factors throughout the material production phase of the building.

Internal Organ Colonization by Salmonella Enteritidis in Layer Pullets Infected at Two Different Ages During Rearing in Cage-Free Housing.

The poultry-housing environment plays a significant role in the transmission and persistence of the egg-associated pathogen Salmonella Enteritidis in laying flocks. The commercial egg industry is in the midst of a transition toward cage-free housing, but the food safety ramifications of this shift are not yet certain. The present study assessed internal organ colonization by Salmonella Enteritidis in layer pullets reared in cage-free housing and infected at two different ages. Groups of 280 pullets were transferred from the rearing facility (at 9 wk of age in one trial and 15 wk in another) to a containment facility with four isolation rooms simulating commercial cage-free barns with perches and nest boxes (70 birds/room). Twenty-four pullets in each room were orally inoculated with Salmonella Enteritidis immediately after placement in the containment facility. At 1-2 wk postinoculation in each trial, samples of liver, spleen, and intestinal tract were collected from all birds in two rooms for bacteriologic culturing to detect Salmonella Enteritidis. At 21-22 wk of age, samples of spleen, ovary, and intestinal tract were similarly collected and tested from all birds in the remaining two rooms. Among samples collected at 1-2 wk postinoculation, Salmonella Enteritidis was isolated significantly more often from groups of pullets infected initially at 15 wk of age than from those infected at 9 wk (61% vs. 38% of livers, 59% vs. 31% of spleens, and 84% vs. 57% of intestines). Among samples collected at 21-22 wk of age, the frequency of recovery of Salmonella Enteritidis was again significantly greater in birds infected at 15 wk of age than in those infected at 9 wk (16% vs. 6% of spleens, 9% vs. 1% of ovaries, and 26% vs. 10% of intestines). These data suggest that Salmonella Enteritidis infections introduced into flocks during the later stages of pullet rearing have greater potential to persist into the early phase of egg production.

Environmental performance of an autonomous laser weeding robot—a case study

PurposeChallenges in sustainable development envisioned in the European Union for the agricultural sector require innovation to raise the efficiency of production and safety of farming processes for farmers and ensure food safety for consumers. One of the key productivity factors in plant production is effective weeding. The WeLASER project aimed to develop a high-power autonomous vehicle with lasers to control weeds. To be sustainable, the invention should have a high environmental performance in the whole life cycle perspective, including its production, use in agriculture, and end-of-life phase. In the publication, a life cycle assessment (LCA) of the WeLASER weeding robot is presented. The aim was to identify weak and strong aspects of the invention in environmental terms and provide suggestions for its improvement.MethodsThe machinery was characterized based on technical data provided by the developers, relevant literature, Ecoinvent 3.8 database, and own calculations. The quantitative assessment of environmental impacts was performed using the Simapro tool. For interpretation Recipe 2016 method (egalitarian perspective) was applied.ResultsThe results show that the energy issue related to autonomous laser-based weeding machine operations is the most challenging. It is related to impacts on climate change indicators and fossil fuel depletion. Production phase is characterized with impacts on human toxicity and is related to extensive application of electronic and electric components in the robot.ConclusionIn comparison with other weeding techniques, the high-power autonomous vehicle with lasers to control weeds shows potential for environmentally efficient use of the machinery in practice. Achieving high performance in the life cycle perspective requires improvements in the design, operational features, and smart application in agricultural practice enhanced through expertise, guidance, and advice.

10Boron-film-based gas detectors at ESS

The development of detectors for the European Spallation Source is an important parallel element to the effort put into the design and construction of the neutron source and instruments. The 10Boron-film-based detector developments that started over a decade ago as basic detector concepts have now reached technical maturity after intense prototyping work and numerous testing campaigns. Several of the ESS beamlines that will soon enter the commissioning phase started welcoming the detector systems built with the 10B-film converter technology. The real-size demonstrators evolved in the last 2–3 years into a diverse suite of gas proportional counters for use in diffraction, reflectometry and small-angle scattering studies in spite of the operational complexity posed by the requirements for large-area coverage, low material budget and robustness for operation in the high-flux and high-radiation environment of ESS. The detectors are now being shipped to ESS or undergoing the last performance and calibration tests before being handed over to the instrument teams for installation in the host beamlines. A common feature of these detector systems is the very large number of readout channels that they are instrumented with in order to fulfill the demanding requirements for sensitivity, spatial resolution and count-rate capability. Across all of the detector types that will operate at ESS, the integration, testing and commissioning of the read-out technologies and software tools for data reduction, calibration and analysis are the focus of the detector and integration teams. These will yield a wealth of knowledge about their operation as well as initial results on the in-situ performance, a very important asset to ensure rapid commissioning of the detectors when neutrons from the ESS source become available. In this paper we will give an overview of the 10B-film-based detector technologies included in the ESS detector suite that are currently facing the transition from the production phase to installation and integration with the other beamline components, which comes with its own specific challenges of both organizational and technical nature.

156 Art as a Multiplier of Science Communication

OBJECTIVES/GOALS: Scientists are increasingly confronted with 'science critical' #_msocom_1 belief systems. The politicization of science fuels hesitancy towards evidence-based therapies. To overcome these barriers, we aim to devise strategies to communicate clinical translational science (CTS) through art. METHODS/STUDY POPULATION: A two-year pilot artist-in-residency (AIR) program embedded in the Translational Research Immersion Program (TRIP). Since 2009, TRIP contributes to CTS Workforce Development (WD) through a 10-week mentored, curriculum-rich summer undergraduate research experience. Students are recruited from 5 regional institutions, 6 HBCUs, and the University of Puerto Rico. AIR is composed of 3 phases: the “Immersive Phase” where the artist gains intensive exposure to the scientific process through the lived experience of TRIP students, the “Productive Phase” where the artist conceptualizes the process of CTS into works of art, and the “Engagement Phase” where the CTS workforce, artists, and community members coalesce around science-to-art materializations. RESULTS/ANTICIPATED RESULTS: In 2022 & 2023 the AIR participated in ~35hrs of CTS research seminars, panel discussions, and professional skills workshops. Additional TRIP student-AIR interaction occurred in focus groups including visits to mentor’s labs. An AIR-led workshop culminated in an Empowering CTS Communication event where TRIP students engaged with community members through elevator pitches of their CTS summer project on a speed-rotating basis. A month-long art-CTS exhibition planned for 3/2024 will feature contributions from AIR, TRIP students, and ITMAT community members. Qualitative insights were that TRIP is an effective art-science incubator, students strengthened their CTS communication skills, art functions as an icebreaker between science and communities with an ocean of opportunities for science education. DISCUSSION/SIGNIFICANCE: AIR embedded into existing CTS WD programs is proposed as creative approach to strengthen the reputation of science in the public. CTS-informed art functions as connective tissue between public and CTS workforce. The hands-on experience to adopt art as a science communication tool is a powerful soft skill for the next generation of CTS investigators.

Transcriptomic responses of rabbits to infections by precocious line and wild-type Eimeria media: revealing molecular signatures and pathway differences in liver and duodenum during the peak and terminal phases of oocyst production.

Eimeria media is a principal pathogen responsible for rabbit coccidiosis, targeting the rabbit's intestinal epithelial cells. This parasitism damages the intestinal mucosal barrier, initiating a systemic immune and inflammatory response that jeopardizes the sustainable growth of rabbit farming. To understand the implications of infection on the host's immune and metabolic responses, we employed RNA-Seq to analyze RNA from the liver and duodenum tissues of post-infected rabbits infected with both the precocious line and wild-type strain of E.media. Comprehensive transcriptomic analysis revealed that the two parasites exhibit divergent transcriptomic imprints on host tissues. While the precocious line predominantly modulates immune-centric pathways with significant differential gene enrichment, wild-type strain favors pathways that affect metabolism. In addition, our study pinpointed a set of genes that undergo significant modifications in response to these effects. These revelations grant a fresh avenue to probe deeper into the symbiotic intricacies of the E.media and its rabbit host.

Recent advances in in-vitro meat production – a review

Abstract In-vitro meat production has entered into the phase of pilot-commercial scale production from the conceptual-laboratory phase. The main challenge for in-vitro meat production on a commercial scale is the very high cost of its production, mainly due to the cost of cell culture media, growth regulators, and the requirement of highly skilled manpower. The development of serum-free and animal-free culture media with plant, microbial, and fungi-derived compounds through recombinant technology and media recycling is crucial for scaling up in-vitro meat production and reducing the price of the end products. The proper design of bioreactors specific to in-vitro meat production, their automation, utilization of natural and edible scaffolds, and microcarriers made up of edible materials are the present focus of researchers. The co-culturing by proliferating various cells such as adipocytes, chondrocytes, fibroblasts, and endothelial cells are applied for imparting textural and organoleptic attributes to developed products similar to conventional meat. The industrial process to produce in-vitro meat needs a clear synergy between the biological, chemical, technical, and industrial fields because at the moment the main research focus is on the development and improvement of cell lines available to set up cell culture and culture media, bioreactors, cell lines, scaffolding, and biofabrication. The research on in-vitro meat is limited by the fact that from the industry the protocols are not properly divulgated.

Quantitative assessment of customer segment, value proposition and appropriateness of minimum viable product features for technology commercialization in the environmental sciences

Transitioning fundamental and applied science to evidence-based real-world applications is challenging yet necessary, especially in environmental sciences. In this paper, a quantitative data analysis method is presented to support decision-making by augmenting qualitative customer discover methods used for new technology adoption. This method can be used to assess: i) customer segment (CS) and value proposition (VP) validity and ii) the ability of a new technology to address the VP. Two different environmental technologies were evaluated to demonstrate this quantitative approach. CS and VP(s) that were previously qualitatively identified were statistically (in)validated using binomial testing. In each of the presented cases, the CS was statistically validated but only one of the three VPs for each case was validated. The validated performance parameters for each technologywere tested against cost and performance data using linear optimization. This testing allowed for the identification of conditions under which the technology met minimum customer performance requirements and where further data or technology modifications were still needed. These identified conditions establish the features necessary to transition the technologies to the minimum viable product (MVP) phase of commercialization. One technology was found to be ready for MVP development while the other technology needed additional data and modification. Both findings demonstrate the effectiveness of this quantitative data analysis method and guide decision-making in the early stages of technology commercialization.

Opening the black box of the use phase in circular economy life cycle assessments: Environmental performance of shell jacket reuse

AbstractLife cycle assessment (LCA) is highly needed and widely used to assess the environmental performance of circular economy (CE) measures such as reusing and sharing. However, the results of such LCAs are hampered by limited knowledge about the use phase of consumer products and oversimplification of important use phase aspects such as product functionality, user behavior, displacement, and rebound effects. This paper aims to validate the usefulness of a framework designed to assist practitioners in the generation and utilization of such knowledge in LCAs of circular measures. To validate the framework, a case study is used: reuse of shell jackets enabled by “premium secondhand” stores for outdoor equipment and clothing. The paper demonstrates that conclusions about the environmental performance of reuse can easily be altered depending on the functional unit definition, whether real user behavior data are used, and whether imperfect displacement and rebound effects are considered. For instance, shell jacket life cycles that include reuse and thus may be labeled “circular” have significantly higher environmental impact per use occasion than “linear” ones (used by one principal user the entire lifespan), since “circular” shell jackets are used less frequently, in particular during their first use span. Through facilitating the generation and utilization of environmentally relevant use phase data, which are otherwise often overlooked, the framework seems capable of supporting a better understanding of the environmental performance of CE measures.

Effect of glass powder on mechanical properties and electromagnetic transmission properties of high alumina cement paste

The mechanical properties and electromagnetic transmission properties of high alumina cement (HAC) paste with different glass powder (GP) contents were investigated in this paper. The effects of hydration phase, unhydrated phase, GP phase and pore phase on the dielectric properties of HAC paste were quantitatively analyzed. The results show that the strength, fluidity and setting time of HAC paste decrease with the increase of GP replacement rate. The real part, imaginary part and loss angle tangent of dielectric constant decrease. The addition of GP leads to a reduction in reflectivity and absorptivity of electromagnetic waves in the paste, while increasing transmittivity.Furthermore, the real part of the dielectric constant of each phase in the HAC paste follows the order: hydration product phase > unhydrated phase > GP phase > pore phase. With an increase in GP content, the real part of the dielectric constant of the hydration product phase increases. Finally, based on the results of vector network analysis (VNA), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM), the reasons for the changes of mechanical properties and electromagnetic properties of HAC paste under different GP replacement rates were analyzed from the aspects of phase composition, pore distribution and microstructure.

A life cycle assessment of clinker and cement production in Ethiopia

Cement production is a major consumer of energy and the largest source of industrial CO2 emissions. This study aims to perform an environmental life cycle assessment of clinker and cement production in Ethiopia, using ReCiPe impact assessment method. Inventory data (material, energy, and transportation) is collected from seven major Ethiopian cement industries. The midpoint analysis identified nine hotspot environmental concerns: global warming, ozone formation (human health and terrestrial ecosystem), particulate matter formation, terrestrial (acidification and ecotoxicity), freshwater eutrophication, human carcinogenic toxicity, and fossil resource scarcity. Human health emerged as the most significantly affected endpoint damage category by the midpoint impacts. Among the process stages included in clinker system boundary, clinker production phase (kiln emissions) is a significant contributor to the total score of the hotspot impacts, ranging from 60.7% to 91.8%. The clinker system is responsible for over 81.03% of the overall environmental burden of cement. The sensitivity analysis reveals that a 5% change in kiln energy consumption and transportation burden could lead to a reduction in hotspot impacts ranging from 1.8% to 5%. To foster reliability of this study, uncertainty analysis is also conducted. Overall, the findings indicate the need to enhance environmental sustainability in Ethiopian cement production.

Enhancing Sustainability in Italian Water Supply Pipes through Life Cycle Analysis

The primary concern regarding the sustainability of the urban water cycle remains the performance of water supply systems. This, in turn, is determined by the functionality and sustainability of the system components, such as the pipe networks, pumps, and other appurtenances, which must be analyzed from an environmental perspective. The aim of the present study is to analyze the sustainability of two different types of water supply pipe materials that are commonly used, polyvinyl chloride and high-density polyethylene, using a comparative Life Cycle Analysis methodology. The functional unit was established in accordance with the water supply system that serves an Italian metropolitan city with a dimension of 9240 km, as one meter of water supply infrastructure, with 40 years as a life span. A cradle-to-gate analysis was conducted, starting from the production phase of the water pipelines to the maintenance phase, excluding the end of life and disposal phases. The chosen methodology was CML, justified by the fact that the results are more understandable and reproducible. Results comparison revealed a higher environmental impact during the production phase, while the maintenance phase had a very low impact. Notably, PVC pipe in comparison with HDPE material had a higher impact, except in two categories of impact: abiotic depletion and photochemical oxidation. The study contributes to the future development of alternative approaches for sustainable and eco-efficient water supply infrastructure designs and materials.

A Comprehensive Investigation of the Relationship between Fractures and Oil Production in a Giant Fractured Carbonate Field

This study examines the connections between various fracture indicators and production data with an example from one of the giant fields in the Middle East producing complex fractured carbonate lithologies. The field under study hosts two reservoirs with a long development and production history, including carbonates from the Asmari and Bangestan Formations. A fracture intensity map was generated based on the interpretation of image logs from 28 wells drilled within the field. Mud loss data were collected and mapped based on the geostatistical Gaussian Random Function Simulation (GRFS) algorithm. Maximum curvature maps were generated based on Asmari structural surface maps. Comparing the results shows a good agreement between the curvature map, fault distribution model, mud loss map, fracture intensity map, and productivity index. The results of image log interpretations led to the identification of four classes of open fractures, including major open fractures, medium open fractures, minor open fractures, and hairline fractures. Using the azimuth and dip data of the four fracture sets mentioned above, the fracture intensity log was generated as a continuous log for each well with available image log data. For this purpose, the fracture intensity log and a continuous fracture network (CFN) model were generated. The continuous fracture network model was used to generate a 3D discrete fracture network (DFN) for the Asmari Formation. Finally, a 3D upscaled model of fracture dip and azimuth, fracture porosity, fracture permeability, fracture length, fracture aperture, and the sigma parameter (the connectivity index between matrix and fracture) were obtained. The results of this study can illuminate the modeling of intricate reservoirs and the associated production challenges, providing insights not only during the initial production phase but also in the application of advanced oil recovery methods, such as thermal recovery.

Network engineering of organosilica membranes for efficient pervaporation dehydration

In the petroleum industry, the mixing of ethanol (EtOH), isopropanol (IPA), and n-butanol (n-BuOH) with water is a prevalent occurrence in both production and recovery phases. Obtaining the required degree of purity via dehydration poses a significant challenge that needs to be addressed. Pervaporation has emerged as a promising method for separating azeotropic mixtures due to its energy efficiency and independence from vapor-liquid equilibrium constraints. In this study, organosilica precursors, namely 1,2-bis(triethoxysilyl)ethane (BTESE), 1,2-bis(triethoxysilyl)ethylene (BTESEthy), and 1,2-bis(triethoxysilyl)acetylene (BTESA), were utilized for the fabrication of organosilica membranes using the sol–gel method. Subsequently, these membranes were employed for pervaporation dehydration of EtOH, IPA, and n-BuOH. This study investigates the effect of the degree of unsaturation of the bridged group, feed composition, and C atom count of alcohol on membrane dehydration performance. The membranes demonstrated superior separation performance for the n-butanol/water mixtures compared to other alcohol/water systems investigated. In this particular context, BTESE membrane exhibited a significant separation factor, although accompanied by a reduced permeation flux. Conversely, BTESA membrane demonstrated a decreased separation factor but an increased permeation flux. The comparison between gas permeation and pervaporation highlighted that the separation mechanism was primarily governed by molecular sieving through the organosilica membranes.

Eco-efficiency and economic assessment of gypsum-based precast with polymeric waste: A case study

The adoption of sustainable building policies and the society’s increasing emphasis on sustainability underscore the urgent need to evaluate the environmental and economic impact of construction materials. This study examines the effects of incorporating polyurethane foam waste into gypsum-based ceiling tiles. It compares its economic performance and eco-efficiency with conventional alternatives. Methodologically, Life Cycle Cost Analysis (LCCA) quantifies total life cycle costs, followed by Eco-Efficiency Assessment (EE), considering results from both Life Cycle Assessment (LCA) and LCCA. Our findings reveal a compelling 5.91% cost advantage for the novel precast, driven by enhanced production capacity resulting from shorter drying times. The economic benefits of this approach are underscored by a detailed breakdown of cost savings in production phases. Furthermore, the EE remarks a substantial 7.5% boost, emphasizing the positive environmental impact achieved through reduced resource consumption and lower emissions combined with lower life-cycle costs. These results highlight the economic viability and eco-efficiency of polymeric waste-integrated gypsum ceiling tiles for environmental sustainability. The specific percentage improvements in cost and eco-efficiency provide a quantitative basis for understanding the advantages of adopting these innovative materials.

Are electric vehicles really the optimal option for the transportation sector in China to approach pollution reduction and carbon neutrality goals?

Profound worldwide fleet electrification is thought to be the primary route for achieving the target of carbon neutrality. However, when and how electrification can help mitigate environmental impacts and carbon emissions in the transport sector remains unclear. Herein, the overall life-cycle environmental impacts and carbon saving range of two typical A-class vehicles in China, including electric vehicle (EV) and internal combustion engine vehicle (ICEV), were quantified by the life cycle assessment model for endpoint damage with localization parameters. The results showed that the EV outperformed the ICEV for the total environment impact after a travel distance of 39,153 km and for carbon emissions after 32,292 km. The ICEV was more carbon-friendly only when the driving distance was less than 3229 km/a. Considering a full lifespan travel distance of 150,000 km, the whole life-cycle average environmental impacts of EV and ICEV were calculated as 8.6 and 17.5 mPt/km, respectively, but the EV had 2.3 times higher impacts than the ICEV in the production phase. In addition, the EV unit carbon emission was 140 g/km, 46.8% lower than that of the ICEV. Finally, three potential reduction scenarios were considered: cleaner power mix, energy efficiency improvement and composite scenario. These scenarios contributed 19.1%, 13.0% and 32.1% reductions, respectively. However, achieving carbon peak and neutrality goals in China remains a great challenge unless fossil fuels are replaced by renewable energy. The research can provide scientific reference for the method and practice of emission reduction link identification, eco-driving choice and emission reduction path formulation.

MD investigation on the differences in the dynamic interactions between the specific ligand azamulin and two CYP3A isoforms, 3A4 and 3A5

The unmarked potential drug molecule azamulin has been found to be a specific inhibitor of CYP3A4 and CYP3A5 in recent years, but this molecule also shows different binding ability and affinity to the two CYP3A isoforms. In order to explore the microscopic mechanism, conventional molecular dynamics (MD) simulation methods were performed to study the dynamic interactions between two isoforms and azamulin. The simulation results show that the binding of the ligand leads to different structural properties of two CYP3A proteins. First of all, compared with apo-CYP3A4, the binding of the ligand azamulin can lead to changes in the structural flexibility of CYP3A4, i.e., holo-CYP3A4 is more flexible than apo-CYP3A4. The structural changes of CYP3A5 are just the opposite. The ligand binding increases the rigidity of CYP3A5. Furthermore, the representative structures of the production phase in the MD simulation were in details analyzed to obtain the microscopic interactions between the ligand azamulin and two CYP3A isoforms at the atomic level. It is speculated that the difference of composition and interaction of the active sites is the fundamental cause of the change of structural properties of the two proteins. Communicated by Ramaswamy H. Sarma

Assessment of four different dietary amino acid profiles recommended for ISA Brown layer hens: A validation study

The current feeding study was designed to validate the two dietary essential amino acid profiles (EAAP) established based on linear broken-line (LBL) and quadratic broken-line (QBL) models, in a previous study, against Evonik (AMINOHen) and breeder recommendations for ISA Brown layers for peak production (PP, 20 to 44 weeks of age), and post peak production (post PP, 44 to 75 weeks of age). The EAAP based on LBL models on average had 19.5% and 26.0% lower digestible AA (Lys, Met + Cys, Thr, Trp, Ile and Val), than the EAAP based on QBL models for PP and post PP, respectively. The EAAP based on AMINOHen and breeder recommendation had lower digestible AA than QBL, and higher EAAP than LBL models for both production phases. At 20 weeks of age, 224 ISA Brown layer hens were weighed and randomly allocated to individual battery cages. Each of the four diets was replicated 8 times with 7 birds per replicate. Egg production was recorded daily, and egg weights were measured at the end of each week. Feed consumption was measured at the end of each period. The egg production rate was not significantly affected by the diets and remained at around 98.0% (PP) and 95.0% (post PP) (P > 0.05). Birds fed diets based on LBL recommendation consistently laid smaller eggs, resulting in a lower egg mass (59.8 vs. 62.0 g egg/hen per day during PP, and 60.3 vs. 63.0 g egg/hen per day during post PP; P < 0.05). Diets had no significant effect on feed intake and body weight (P > 0.05). The highest feed conversion ratio (FCR) during PP (P = 0.067) and post PP (P < 0.05) was recorded for the birds offered diets based on LBL recommendation. In conclusion, all four EAAP tested in this study support an above average egg production rate. However, the EAAP based on LBL models may potentially decrease the input feed cost per kilogram of eggs but are not set to optimise FCR and maximise egg mass.

Determination of energy consumption according to the phases of the mineral comminution process [Determinación del consumo energético según las fases del proceso de conminución de minerales

The objective of the research was to study the equations used in energy expenditure for the mineral comminution area and its importance. The focus of the article was theoretical, in which bibliographic information from different convincing and reliable sources of information was grouped, which were analyzed and summarized in graphs and tables to better understand the information; Likewise, the importance that these have in the mineral commercialization process and the production phases where the equations are used was made known; For a better understanding, it is necessary to know about the energy used by the elements where the crushing and grinding stages occur. The equations studied to find this energy are four; the specific energy equation, Rittinger's postulate, Kick's postulate and Bond's postulate, all explained with their characteristics and the data they consider to be resolved. Subsequently, a comparison of their main differences was presented in addition to a practical example where The three equations and the procedure to solve them were applied. We conclude that the importance of the Rittinger, Kick and Bond equations lies in the need for them to calculate costs and to begin the commercialization of minerals, the energy consumed above all will depend on the characteristics of the rock, such as size, type of valuable mineral present and the stage of comminution in which they are found.

A profit-cost ratio maximization approach for a manufacturing inventory model having stock-dependent production rate and stock and price-dependent demand rate

This paper discusses an optimal managerial approach regarding stock control in a manufacturing-inventory scenario. The selling price and inventory level in showrooms may impact customers’ demand. The fall in selling price creates additional demand, while shown inventory also positively enhances demand. In this paper, demand is influenced by the selling price during the productive phase and the displayed stock in idle time. The significance of selling price and stock on profit goal may not be inherited from that of the demand function. The production rate varies negatively against the inventory on hand. Instead of taking cost minimization or the profit maximization objective, this paper executes an optimization approach on the profit-cost ratio function, sharpening the manufacturer’s goal. The numerical solution and sensitivity analysis on optimal outcomes succeed the analytical solution in Mathematica software. Numerical results indicate that the profit-cost ratio rises with selling price, suppressing the negative impact of the selling price on demand. Also, the profit-cost ratio shows a concave curve for the production cycle, ensuring a global maximum for the objective function.