Effect Of Storage Time Research Articles

Variability of 7K and 11K SomaScan Plasma Proteomics Assays.

SomaScan is an aptamer-based proteomics assay designed for the simultaneous measurement of thousands of human proteins with a broad range of endogenous concentrations. The 7K SomaScan assay has recently been expanded into the new 11K version. Following up on our previous assessment of the 7K assay, here, we expand our work on technical replicates from donors enrolled in the Baltimore Longitudinal Study of Aging. By generating SomaScan data from a second batch of technical replicates in the 7K version as well as additional intra- and interplate replicate measurements in the new 11K version using the same donor samples, this work provides useful precision benchmarks for the SomaScan user community. Beyond updating our previous technical assessment of the 7K assay with increased statistics, here, we estimate interbatch variability, assess inter- and intraplate variability in the new 11K assay, compare the observed variability between the 7K and 11K assays (leveraging the use of overlapping pairs of technical replicates), and explore the potential effects of sample storage time (ranging from 2 to 30 years) in the assays' precision.

Investigation of thermal properties of TiN/MWCNT-OH hybrid nanofluids and GWO-BP neural network model

Hybrid nanofluids have garnered significant attention due to excellent heat transfer performance and potential applications. Conducting comprehensive research on hybrid nanofluids holds paramount importance. This study investigates the effects of surfactants, particle concentrations, mixing ratio and storage time of TiN/MWCNT-OH hybrid nanofluids on stability, thermal conductivity, and viscosity. It proposes a Grey Wolf Optimizer-Backpropagation neural network model for predicting thermal properties. The results indicate that the inclusion of PVP-K30 surfactant leads to remarkable stability of hybrid nanofluids at a concentration of 50 ppm over a period of two weeks. An increase in the proportion of MWCNT-OH results in a slight increase in thermal conductivity, which exhibits a maximum increase of 46 % with elevated temperature and particle concentrations. The viscosity of hybrid nanofluids gradually decreases as temperature rises, although demonstrates a non-linear correlation with concentrations. The neural network model exhibits a high predictive accuracy of 99.3507 % for thermal conductivity and 98.8924 % for viscosity.

Proteomic analysis of wild boar meat: Effect of storage method and time on muscle protein stability

Oxidation processes affect proteins from various molecular pathways and are crucial for wild boar meat quality, shelf life and human health. This study investigated the effects of different storage methods on the formation and composition of oxygen-induced protein aggregates in the muscles of European wild boar (Sus scrofa scrofa). Vacuum packaging (VAC), modified atmosphere packaging (MAP) and dry-ageing (DA) were compared over a 21-day storage period. The results showed significant differences in protein aggregation depending on the method and storage time. The most intense protein aggregation occurred in the MAP (80 % O2), while air DA (20.9 % O2) resulted in intermediate levels of protein aggregation. Crucial myofibrillar proteins involved in aggregate formation were titin, myosin isoforms (MYH1, MYH2 and MYH7) and nebulin, which were cross-linked with small sarcoplasmic enzymes, such as muscle creatine kinase, isocitrate dehydrogenase and ATPase 1. High‑oxygen storage conditions also promoted the oxidation of ATP synthase, beta-enolase 3, ADP/ATP translocase and myoglobin.

Effect of Storage Conditions and Time on the Dimensional Stability of 3D Printed Surgical Guides: An InVitro Study.

To evaluate the dimensional stability over time of additively manufactured surgical templates, fabricated by different resins, and stored by different methods. Using a 3D printer with DLS technology and two different resins (Surgical Guide (SG)-WhipMix and Key Guide (KG)-KeystoneIndustries), 96 surgical guides were additively manufactured. The guides were stored in three different environments: directly exposed to sunlight (S1), in normal interior room conditions (S2), and in darkness (S3). The guides were digitally scanned immediately after fabrication and post-processing, and after 1, 3, and 6 months of storage. For each group, the mean deviation of the root mean square (RMS) between guide's intaglio surface, as well as the axial deviation between sleeves' housings were calculated. The mean axial variations of angular axis deviation of sleeves' housings ranged between 0.09° and 3.99°. The mean deviation of the RMS discrepancy in guide's intaglio ranged from 0.1 to 0.18 mm. Variations were significant (p < 0.001) only for the S1 group and only for SG material. After 3 months, an additional storage time of 3 months did not have any further effect on dimensional stability. Within the limitations of the present study, storage time of a surgical guide for up to 3 months after manufacturing, as well as printing material can significantly affect surgical guide's dimensional stability, when they are exposed to direct or indirect sunlight conditions. Storage of guides in a dark environment is recommended in order to avoid an additional source of error in computer-guided surgery workflows.

Effect of hot red pepper supplementation and different storage time on hens egg quality

Introduction. Eggs are a food source of protein that easily deteriorates during storage. Supplementation of hot red chilli pepper powder rich in bioactive compounds in diets for laying hens can improve egg quality and prevent egg deterioration during storage. Objective. To determine the effect of hot red pepper powder supplementation and different storage times on the physical egg quality of laying hens. Materials and methods. This study was conducted from January to March 2024 at the Research Barn of PT. Agromix Lestari Group, Kulon Progo, Yogyakarta, Indonesia. Eighty 56-week-old Novogen laying hens (1681 ± 64 g) were assigned into four dietary treatments (4 replications, 5 hens per replication): basal diet as control (P0); basal diet + 0.25 % hot red pepper powder (P1); basal diet + 0.5 % hot red pepper powder (P2); and basal diet + 0.75 % hot red pepperpowder (P3). At the end of week 6, one egg per replicate group was collected and analyzed for physical quality in three storage treatments: fresh condition (S0), one week storage (S1), and two weeks storage (S3). Egg quality data were analyzed with a factorial experimental design (4 x 3) using SPSS 26 software. Results. Supplementation of 0.5 % hot red pepper powder significantly increased egg weight. Hot red pepper addition and treatment duration significantly affected egg yolk colour. The hot red pepper treatment group showed significantly lower pH of albumen and yolk. Conclusions. The supplementation of hot red pepper powder in laying hens diets has been shown to improve the egg yolk color. The inclusion of 0.5 % in the ration was able to keep the pH of yolk and albumen low.

Effect of Fermentation Technology and Storage Time on the Quality of Salami-Type Sausages

The fermentation process is a crucial stage in the production of salami-type sausages. However, the traditional (“warm”) method does not yield optimal results. Hence, this study evaluated the impact of fermentation technology and storage time on the quality attributes of salami-type pork sausages. “Warm”-fermented (WF) and “cold”-fermented (CF) sausages were produced using appropriate starter cultures. Following ripening, the products were stored for 63 days under cooling conditions. The evaluations encompassed microbiological and physicochemical characteristics (pH, aw, color), basic chemical composition (NIR spectroscopy), the degree of fat hydrolysis (acid value) and oxidation (TBARS index), textural properties (TPA, shear/penetration test), and sensory (hedonic) attributes. In both sausages, mesophilic aerobes and lactic acid bacteria were the dominant microflora immediately after ripening. While the chemical composition of the salami remained constant during storage, there was a slight color change. WF sausages exhibited a significantly higher acid value and TBARS index than CF sausages. Over time, the internal structure of WF sausages became more porous, deteriorating the texture. In addition, CF sausages showed better sensory characteristics. In conclusion, using “cold” fermentation enhanced the quality and durability of salami-type sausages. This approach shows promise for industrial-scale production and aligns with consumer preferences.

PSXII-22 Ruminal in situ dry matter and starch degradability in grain sorghum silage, as affected by processing and storage time

Abstract Our previous studies showed that processing sorghum silage at harvest and storing for approximately 150 d, improved average daily gain (ADG), feed efficiency (FE) and apparent total tract digestibility (ATTD) of starch when included as the basal ingredient in diets fed to growing Angus heifers. However, differences in animal performance and nutrient digestibility disappeared when the same sorghum silage was fed again after 1 yr of storage. An experiment was performed to evaluate the effects of kernel processing and storage time on ruminal in situ degradability of sorghum silage (SS). A grain sorghum (ADV2450IG, Advanta seeds, Irving, TX) was harvested (Claas Jaguar 930, Harsewinkel, Germany) at the late-dough stage of grain maturity. Treatments were applied at harvest and consisted of sorghum berry processing (PRO) with a specific SS kernel processor (196 mm rolls of 125 teeth each, 40% speed differential, 1.1 mm roll gap), or not processed at all (NPR). Silage was chopped at 15 mm theoretical length of cut and ensiled in polyethylene ag bags (60 m long and 2.74 m diameter), for 455 d. Samples were taken from each treatment on d 0, 66, 112, 157, 202, 246, 291, 336, 381, 426, and 455 and were kept frozen until analyzed. Samples were dried but not ground, to avoid affecting treatments. Ruminal in situ degradability of dry matter (DM) and starch was determined by incubating nylon bags for 24 h in duplicate, in the rumen of four ruminally cannulated steers consuming a corn silage-based diet. Data were analyzed as a randomized block design with repeated measures. The fixed effect of treatment, day and their interaction were included in the model and the repeated subject was considered the animal within treatment. A storage day × treatment interaction was detected for in situ DM degradability (P &amp;lt; 0.001). The PRO treatment increased (P &amp;lt; 0.05) in situ DM degradability at 66 and 202 d of storage and tended to increase it (P = 0.07) at 157 and 291 d of storage. An effect of storage day (P &amp;lt; 0.05) was observed for in situ starch degradability and because there was no interaction with treatment (P = 0.43), treatments means were compared across storage days. No differences were detected in ruminal in situ digestibility of DM or starch when silage was stored for 202 d, when compared with d 0 (P = 0.43), while starch degradability increased when silage was stored for 202 and 291 d (P &amp;lt; 0.03). At 381 d of storage, no differences were detected for starch degradability when compared with d 0. In conclusion, berry processing of sorghum when harvested for silage, increased ruminal in situ DM degradability. However, those differences disappear after more than 200 d of storage, in agreement with animal performance data previously reported by our group.

Effect of Storage Time on the Structural Integrity of Silts and Organic Soils: An Analysis of Moisture Content, Unconfined Compressive Strength, and Elasticity

The impact of storage duration on the geotechnical properties of soils is a recurring issue in the field of geotechnical engineering. Due to the lack of previous research addressing this topic, an experimental study was conducted to evaluate the variation of these properties over time. Undisturbed samples of silty and organic soil from Quito, Ecuador, were obtained. These samples were subjected to unconfined compressive strength (UCS) and moisture content (MC) tests at various intervals (1, 3, 7, 14, 21, 28, and 56 days). Results revealed a significant correlation between MC, UCS, and modulus of elasticity (ME). A progressive increase in UCS and ME was observed as MC decreased, with peak values observed to occur between 20 and 30 days. These findings suggest that matric suction plays a predominant role in increasing cohesion and, consequently, UCS. Therefore, it is concluded that the time elapsed between sample extraction and testing is a critical factor influencing the preservation of MC and, hence, the accurate assessment of the soil’s mechanical properties.

BD Vacutainer™ Urine Culture & Sensitivity Preservative PLUS Plastic Tubes Minimize the Harmful Impact of Stressors Dependent on Temperature and Time Storage in Uropathogenic Bacteria.

Background: Urinary tract infection is a worldwide health problem. According to the Clinical Laboratory Improvement Amendments and the European Urinalysis Guideline, urine samples should be tested within 2 h of collection. Thus, using chemical preservatives that guarantee the pre-analytical conditions is a practical tool. However, the effects of temperature and storage time as uropathogenic bacteria stressors are unclear. Methods: Gram-negative and -positive ATTC strains, E. coli, P. mirabilis, E. faecalis, and S. aureus, were used in this study. Strains in liquid media were stored at 4, 25, and 37 °C for 0, 2, 12, 24, and 48 h in tubes with and without preservatives. Then, reactive oxygen species (ROS) levels, viable but non-culturable bacteria (VBNC), and bacteria growth were analyzed. Results: A high ROS level was associated with the presence of VBNC and dead bacteria with low CFU counts, but a low ROS level increased the CFU number, depending on temperature and storage time in tubes without preservatives (boric acid, sodium borate, and formate). The BD Vacutainer™ Urine Culture & Sensitivity Preservative PLUS Plastic Tubes (C&S-PP) prevent this ROS increase, maintaining the CFU number for longer. Conclusions: C&S-PP tubes minimize the stressor effects (temperature and time storage) on uropathogenic bacteria when stored, improving the pre-analytical conditions of cultures realized by the clinical laboratory.

Effect of Storage Duration on the Insecticidal Activity of Neem (&amp;lt;i&amp;gt;Azadirachta indica&amp;lt;/i&amp;gt;) Seeds Against Fall Armyworm (&amp;lt;i&amp;gt;Spodoptera frugiperda&amp;lt;/i&amp;gt;)

Neem (&amp;lt;i&amp;gt;Azadirachta indica&amp;lt;/i&amp;gt;), native to India, thrives in tropical and sub-tropical climates. Its efficacy against economically significant pests is attributed to the pesticidal properties found in its leaves, bark, and roots. Neem seeds are always harvested by smallholder farmers and stored for use in crop-growing seasons when their availability is scarce. This study aimed to determine if storage duration can affect the toxicity of these neem seeds. Neem seed extracts were tested for toxicity after being stored at different durations, they were stored for 1-3 years. The objective of this study was to analyze the effects of storage time on the insecticidal activity of neem seeds. Fall armyworm larvae were used to test for the neem seed extracts’ toxicity by feeding on maize plants which were sprayed with these extracts. The experimental design used was a complete randomized design in the laboratory. Extracts were made from neem seeds stored for 1-3 years which were harvested from year 2019, 2020, 2021 and 2022. Analysis of FAW larvae mortality at different concentrations (0.5%, 1.0%, 1.5%, and 2.0%) together with the control treatment under laboratory conditions was done. Damage severity rates of maize leaves in which the FAW larvae were allowed to feed were measured and FAW larvae mortality was calculated. The results showed a significant interaction between neem seed storage time and FAW mortality. The results showed that extracts from fresh neem seeds and those stored for one year had the lowest plant damage score. Also, the lowest mortality was obtained from seeds stored for 1 year and the fresh seeds because the larvae refrained from feeding. Following this study, we recommend the usage of fresh neem seeds and those stored for up to a year in the management of fall armyworms.

Evaluating the impact of storage time and temperature on the stability of bioactive compounds and microbial quality in cherry syrup from the ‘Burlat’ cultivar

This study aimed to investigate the effect of storage time and temperature on the bioactive and sanitary quality of cherry syrup made from the “Burlat” cultivar cherries. The syrup was pasteurized at 70 °C for 2 min and stored at four temperatures (− 20, 4, 28, and 40 °C) for six months. The total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC), and antioxidant activity (AA) of the syrup were monitored throughout the storage period. Results showed that there was no statistically significant loss of TPC, TFC, TAC, and AA up to 60 days of storage at − 20 °C and 4 °C (p < 0.05). However, at 28 °C and 40 °C, a significant loss was observed from 30 days of storage. ATR-FTIR analysis confirmed the degradation of syrup nutritive compounds around the vibration regions attributed mainly to proteins and phenols as a function of temperature and storage time. Microbial control revealed that no molds or yeasts were detected at any temperature treatment during the 6-month storage period. Overall, this study suggests that low temperature storage (− 20 °C) is recommended to maintain the microbiological and biochemical quality of cherry syrup. As a result, the findings from this study will prove valuable to a wide range of industries, including food, nutrition, pharmaceuticals, and therapeutics.

Effects of Time Storage, Egg Yolk Concentration and Semen Washing on Sperm Motility in Arbia Bucks

Abstract With a prospect to improve goat artificial insemination, this study aims to evaluate the effects of storage time, egg yolk concentration and semen washing on the rate of motile spermatozoa (spz) in Arbia breed bucks semen stored at 5 °C for 48 h. Semen was collected from three mature bucks using an artificial vagina during December 2018. The ejaculates used in this study (rate of motile sperm &gt; 75 %) were divided into two fractions: A, and B, (unwashed and washed samples, respectively): themselves divided into three fractions, and diluted in Tris-Acid citric based extenders, containing egg yolk at 2 %, 10 % and 20 %. ANOVA test was performed using the R software version 3.3.0. The rate of motile spermatozoa was evaluated after 24 and 48 hours of storage in the refrigerator at 5 °C. It registered a significant decrease as a function of the storage time in the different extenders. It varied between 42.43 ± 9.86 % and 61.29 ± 5.44 %, after 24 hours of storage, and between 35.86 ± 13.95 %, and 55.45 ± 11.65 % after 48 hours of storage. The semen washing significantly reduced the rate of motile spermatozoa in the different extenders. Increasing the concentration of egg yolk in the extender increased the rate of motile spermatozoa, especially during the first 24 hours of storage. In conclusion, the rate of spermatozoa motility of unwashed semen stored at 5 °C is higher in extenders containing high egg-yolk concentration, and decrease according to conservation time.

Effects of Storage Time and Temperature on the Fermentation Characteristics of Rumen Fluid from a High-Forage Diet

The objective of this experiment was to investigate the effects of storage temperature and preservation time on the fermentation characteristics of rumen fluid collected from six Hu sheep fed a high-forage diet. The storage temperatures were set at −80 °C and −20 °C, and the preservation times were labelled as follows: 0 d (fresh rumen fluid, D0), 7 d (D7), 14 d (D14), 30 d (D30), 60 d (D60), 120 d (D120), and 240 d (D240). A repeated-measures design was applied to analyze the fermentation characteristics of rumen fluid across each preservation time point and storage temperature. The results showed that storage temperature had no significant effects on pH value, ammonia nitrogen (NH3-N), microbial protein (MCP), and volatile fatty acid (VFA) concentration and proportion (p &gt; 0.05). Specifically, the pH value increased on D7, D14, and D60 (p &lt; 0.05), while the MCP concentration decreased on D7, D14, D30, D120, and D240 but increased on D60 (p &lt; 0.05), and the concentration of NH3-N decreased on D14 (p &lt; 0.05). The acetate concentration increased on D30, while the concentrations of propionate, butyrate, valerate, and total VFA increased on D60 (p &lt; 0.05). The concentration of isovalerate decreased on D60, and isobutyrate and branched-chain VFA concentrations decreased on D120 (p &lt; 0.05). The proportion of acetate increased on D30, while the butyrate and valerate proportions increased on D60, and the proportions of isovalerate, isobutyrate, and branched-chain VFA decreased on D60 (p &lt; 0.05). For rumen fluid from a high-forage diet, the storage temperature (−80 °C and −20 °C) did not affect its fermentation characteristics, suggesting that rumen fluid could be preserved at −80 °C or −20 °C without altering its fermentation characteristics. The fermentation parameters of rumen fluid changed significantly after 7 days of preservation; hence, it is recommended to finish determining the fermentation parameters of rumen fluid within 7 days of collection. The concentrations and proportions of most VFA changed after 30 days of preservation; therefore, it is recommended that VFA determination should be completed within 30 days of rumen fluid collection.

Deeper insight into the storage time of food waste on black soldier fly larvae growth and nutritive value: Interactions of substrate and gut microorganisms

Biological treatment of food waste (FW) by black soldier fly larvae (BSFL) is considered as an effective management strategy. The composition and concentrations of nutrients in FW change during its storage and transport period, which potentially affect the FW conversion and BSFL growth. The present study systematically investigated the effect of different storage times (i.e., 0–15 d) on FW characteristics and its substantial influence on the BSFL growth. Results showed that the highest larvae weight of 282 mg and the shortest growth time of 14 days were achieved at the group of FW stored for 15 days, but shorter storage time (i.e., 2–7 d) had adverse effect on BSFL growth. Short storage time (i.e., 2–4 d) improved protein content of BSFL biomass and prolonged storage time (i.e., 7–10 d) led to the accumulation of fat content. The changes of substrate characteristics and indigenous microorganisms via FW storage time were the main reasons for BSFL growth difference. Lactic acid (LA) accumulation (i.e., 19.84 g/L) in FW storage for 7 days significantly limited the BSFL growth, leading to lowest larvae weight. Both the substrate and BSFL gut contained same bacterial communities (e.g., Klebsiella and Proteus), which exhibited similar change trend with the prolonged storage time. The transfer of Clostridioides from substrate to BSFL gut promoted nutrients digestion and intestinal flora balance with the FW stored for 15 days. Pathogens (e.g., Acinetobacter) in BSFL gut feeding with FW storage time of 7 days led to the decreased digestive function, consistent with the lowest larvae weight. Overall, shorter storage time (i.e., 2–7 d) inhibited the BSFL digestive function and growth performance, while the balance of the substrate nutrients and intestinal flora promoted the BSFL growth when using the FW stored for 15 days.

Effects of storage time and temperature on the aroma quality and color of vanilla beans (Vanilla planifolia) from Taiwan

This study investigated the effects of different storage times (0–24 months) and temperatures (−20 °C, 4 °C, 25 °C, and 35 °C) on the volatile compounds and color of vanilla beans from Taiwan using ISO 5565-1:1999 as the commercial quality indicators. The vanillin level was highest at −20 °C for 6 months (p < 0.05) and no color-perceived differences (ΔE < 1). At 35 °C, lipid metabolism, enzymatic oxidation, and Maillard reaction products, such as 2-acetylpyrrole and 5-hydroxymethylfurfural, were detected after 18 months of storage, leading to significant color-perceived differences (ΔE > 5) and changes in the odor profile, which did not meet ISO standards. To sum up, as the storage temperature and duration increased, oxidative metabolites increased. Furthermore, storage at −20 °C or 4 °C is stable, but considering vanillin quality, the storage temperature of −20 °C can extend the storage period by 12 months.

Evaluation of the effects of storage time and temperature on the beverages

Beverages are an important part of the food sector their storage is also one of the most critical issues. This study investigated the effects of different storage temperatures and times on physicochemical properties, flavonoid and organic acid contents of soda, sherbet and ice tea produced by adding sour grape concentrate. Changes in the flavan-3-ol content of ice tea were also measured during the storage period. The beverages were stored in three different conditions, cold storage (~4°C), room temperature (~24°C) and controlled storage (20±1°C), for six months and analyzed every two months. Storage temperatures and time affected the total soluble solids and acidities of the beverages (p≤0.05). Tartaric acid decreased during storage, especially during the first two months in sherbets. Ice tea and soda drinks were found more stable than sherbets. The malic acid was found the major organic acid in beverages. Flavonoid content in ice tea was higher than others. The flavonoid concentrations of ice tea stored at 20 and 24°C and of sherbet at 4°C were statistically significant as a function of storage time while these values were not significant for ice tea stored at 4°C and of sherbet at 20 and 24°C (p≤0.05). Concentrations of flavan-3-ols varied with storage conditions. The levels of epicatechin, epigallocatechin and epigallocatechin gallate in ice tea samples decreased between an average of 43.72 and 71.15% at the end of six months of storage. Principal component analysis separated two months storage from other storage periods and perfectly discriminated the studied flavan-3-ols except catechin. Soluble solid and brix-acid ratio also dissociated similarly to flavan-3-ols.

Chemical stability and invitro antimicrobial efficacy of diluted silver sulfadiazine powder and cream over a six-month period.

Silver sulfadiazine (SSD) is commonly formulated into otic preparations to treat otitis externa, although evidence of stability and antimicrobial efficacy with long-term storage is lacking. To evaluate the effect of storage time on chemical stability and invitro antimicrobial activity of SSD diluted in sterile water, including two 1% suspensions using SSD pharmaceutical-grade powder stored at room temperature (RT) in plastic or sterile glass bottles, and a 1:9 dilution using prescription SSD 1% cream stored at RT in a sterile glass bottle. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assessed chemical stability. Trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazole-resistant strains of Staphylococcus pseudintermedius (SP), meticillin-resistant (MR) SP, S. schleiferi (SS), MRSS, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli evaluated by 24 h time-kill analysis assessed invitro antimicrobial efficacy. Each assessment was performed at zero, one, three and six months of storage. LC-MS/MS showed no significant change in concentration over time for any suspension. When adjusted for time and species/strain, all SSD suspensions showed significant reductions in colony forming units (cfu)/mL at 24 h (p < 0.001). Including all suspensions, a bactericidal effect (minimum 3-log cfu/mL reduction at 24 h) occurred against 94% of total isolates, with failure against 33 of 552 isolates (6%). Bactericidal failure was more likely with the cream-based suspension (p < 0.05) and at six months (p < 0.01). Powder-based and cream-based SSD/sterile water suspensions showed no significant change in concentration and demonstrated invitro antimicrobial activity for six months. Bactericidal failure was more likely with the cream-based suspension and after six months of storage.

EFFECT OF LONG-TERM STORAGE OF CAJEPUT LEAVES (Melaleuca Leucadendron Linn) ON OIL QUALITY FROM ROTE NDAO REGENCY

Cajeput oil is one of the non-timber forest products produced by distilling Cajeput leaves of the Melaleuca leucadendron Linn type. Several factors influence the quality of Cajeput oil, including filling the leaves in the kettle, tree variety, where the Cajeputi grows, storage of the leaves, distillation techniques, distillation temperature, and age. This research aims to determine the effect of storage time for raw materials on the yield, refractive index, and sineol content of Cajeput oil and the best time to store refining raw materials before distillation. The raw materials for distillation are taken from Rote Ndao Regency and then stored for varying lengths of time ranging from 3 days, 4 days, and 5 days, and the distillation method used is the boil method. The research results showed that the highest average per parameter was obtained after 5 days of storage with a yield value of 2.43%, a refractive index of 1.45%, and a sineole content of 56.67%. The average weight of cineole content and refractive index is included in the Indonesian National Standard (SNI 06-03954-2014).

Effect of Packaging Method and Storage Environment on Activity of Magnesium Oxide and Mechanical Properties of Basic Magnesium Sulfate Cement.

As one of the raw materials of basic magnesium sulfate cement (BMSC), the activity of light-burned magnesium oxide (MgO) has an important effect on the hydration rate, hydration products, and mechanical properties of BMSC. To reveal the influence of packaging method, storage environment, and storage time on the activity of MgO and the mechanical properties of BMSC, an experiment was conducted by using ordinary woven bags, peritoneal woven bags, and plastic and paper compound bags to store the finished BMSC and the raw materials (light-burned MgO, MgSO4·7H2O, fly ash, and a chemical additive) under the conditions of natural environment, sealed environment, and wet environment, respectively. Comparative analysis of the effects of packaging method, storage conditions, and storage time on the activity of MgO and the mechanical properties of BMSC was performed through the mechanical strength test of mortar specimens. The results showed that in a sealed environment, the loss of a-MgO content in light-burned MgO was minimized, which was more conducive to keeping the mechanical properties of BMSC stable. In the wet environment, the mechanical strength of BMSC was significantly reduced in the early stage (1 day) due to the significant reduction in the activity of MgO, and the mechanical strength of the finished BMSC and prepared BMSC after 120 days of storage was still lost, regardless of the packaging method. However, the storage environment and packaging method had relatively little effect on the late mechanical strength (28 days) of BMSC. It is advisable to use ordinary woven bags for packaging in natural and sealed environments as this is more economical for engineering applications. Plastic and paper compound bags are superior to ordinary woven bags and peritoneal woven bags in wet environments.

Effect of moisture content in polyether-ether-ketone (PEEK) filament on 3D printed parts

Polyether-ether-ketone (PEEK) is a recently commonly used high-performance thermoplastic material with high heat resistance, high chemical resistance, high water resistance, and high wear resistance. Polyether-ether-ketone products with complex structures manufactured through the 3D printing process of fused filament fabrication (FFF) are emerging in the medical field. However, similar to other plastics, PEEK materials are also hygroscopic. This may have an impact on 3D printed products. The effect of storage time of filament on 3D printed PEEK products under specific temperature and humidity conditions has not been further explored. This study is mainly to explore the moisture absorption of PEEK filament for different storage time and the effect of moisture absorption on the performance of 3D printed PEEK products. The correlation between storage time and moisture absorption is verified by experiment. It is found that moisture will affect the surface quality of PEEK products. In addition, the mechanical test results show that the increase in the amount of water absorbed leads to the decrease of material properties, such as tensile strength, density, and hardness. Therefore, it is recommended to store unused or leftover PEEK filaments under vacuum drying conditions. For PEEK filaments that are being printed, it should be ensured to replace them every less than 24 h.