Rice is a salt-sensitive crop. The objective of this study was to evaluate the effect of salinity at flowering stage on physiological traits and yield of landrace rice. The experiment design was 4*10 Factorial in RCBD with 4 replications. Factor A was four salinity levels: control, 6, 12 and 16 dS/m; Factor B was 10 rice varieties. Data were collected on physiological traits and grain yield. The results showed that increasing salinity level decreased rice yield. The highest yield reduction was found when the rice received salt stress at 16 dS/m. In addition, rice varieties showed different yield performance when exposed to salt stress. In this found that Hom Yai variety had the lowest yield reduction when grown at 16 dS/m salinity level and did not differ from salt tolerant check variety.
การผลิตข้าวในประเทศไทยยังคงประสบปัญหาเกี่ยวกับสภาพพื้นที่ปลูกข้าวที่ไม่เหมาะสมต่อการเจริญเติบโต ซึ่งทำให้ผลผลิตของข้าวลดลง เช่น ปัญหาดินเค็ม โดยดินเค็มคือดินที่มีปริมาณเกลือที่ละลายน้ำได้ดีอยู่ในสารละลายดินสูงมากจนมีผลกระทบต่อการเจริญเติบโตและการสร้างผลผลิตของพืช อีกทั้งในปัจจุบัน สภาวะโลกร้อนมีความรุนแรงมากขึ้น และมีผลต่อเนื่องทำให้ความเครียดจากความเค็มมีความรุนแรงมากขึ้นด้วย การใช้ข้าวสายพันธุ์ที่มีความทนเค็มเป็นอีกวิธีที่จะช่วยแก้ปัญหาได้อย่างยั่งยืน ดังนั้นในการศึกษาครั้งนี้จึงสนใจศึกษาความเครียดเค็มในระยะออกดอกของข้าวที่ต่อเนื่องไปจนถึงระยะเก็บเกี่ยว โดยทำการศึกษาในพันธุ์ข้าวพื้นเมือง 6 พันธุ์ที่ผ่านการคัดเลือกแล้วว่าทนต่อความเค็มในระยะกล้าเปรียบเทียบกับข้าวพันธุ์ทนเค็มมาตรฐาน Pokkali และพันธุ์การค้า KDML105 ซึ่งผลจากการวิจัยที่ได้ในครั้งนี้สามารถนำไปเป็นข้อมูลพื้นฐานเพื่อใช้ในการปรับปรุงพันธุ์ข้าวให้มีความสามารถในการทนต่อสภาวะเครียดที่เกิดจากดินเค็ม และเป็นการคัดเลือกพันธุ์ข้าวที่มีศักยภาพในการทนเค็ม ตลอดจนส่งเสริมให้เกษตรกรปลูกในพื้นที่ที่กำลังประสบปัญหาจากสภาวะดินเค็มต่อไป
คณะวิศวกรรมศาสตร์
Stirling engine is the external heated engine that heat is sup-plied externally to the heater part of the engine. Thus, Stirling cycle engine can be employed with various sources of renewable energy such as biomass, biofuel, solar energy, geothermal energy, recovery heat, and waste. The integration of gasifier, burner, and heat engine as a power system offers more fuel choices of each local area with potential resources resulting independent from shortage and cost fluctuation of fossil fuel. This research aims to investigate the integration of the Stirling engine with a wood pellet gasifier for electric power generation. Biomass can be controlled to have continuously combustion with ultra-low toxic emission. Stirling engine, therefore, is a promising alternative in small-scale-electricity production. Even though many biomass-powered Stirling engines were successfully constructed and marketed but these engines and the use of biomass resources as fuel for power generation are quite new concepts in some developing countries. Especially, the capital cost of this engine is high and unaffordable for installation compared to other power systems. Therefore, this research aims to the study attractive and feasibility of the compact Stirling engine with green energy.
คณะทันตแพทยศาสตร์
Objective or Background: Dental caries is still one of the most significant dental problems worldwide, with prevalence rates up to 90% among children and adults. Cariogenic bacteria, especially Streptococcus mutans, is the primary microorganism involved in the pathogenesis through carbohydrate metabolism and biofilm formation, which are challenging to eradicate. Histatin-5 (HST-5), a human salivary antimicrobial peptide, has demonstrated antimicrobial activity against various fungal and bacterial pathogens. Phytosphingosine (PHS), an endogenous bioactive sphingolipid found in fungi, plants, and humans, also shows antimicrobial properties. This study aimed to evaluate the killing activity of HST-5 alone and in combination with PHS against S. mutans under biofilm-stimulating conditions. Materials and Methods: Antimicrobial activity against a planktonic culture of S. mutans was evaluated using a time-kill assay, and biofilm-forming capacity was confirmed by crystal violet staining assay. The killing ability against 24h pre-formed biofilm was determined using Transferable Solid Phase (TSP) pin lid model. Synergistic activity between HST-5 and PHS was evaluated using the checkerboard technique. Additionally, the cytotoxicity of the tested agent on human gingival fibroblast cells (hGFs) was assessed after 1 h of incubation using an MTT assay. Results: A time-kill assay revealed that both HST-5 and PHS exhibit time- and concentration-dependent activity against the planktonic form of S. mutans. PHS achieved over 90% killing activity within 15 min at 5 μg/ml, whereas HST-5 required 30 min to reach 90% killing at 20 μM. The biofilm formation capacity of S. mutans was confirmed. The inhibitory concentrations (IC50) of HST-5 and PHS against S. mutans biofilm were 25 μM and 13.5 μg/ml, respectively. A synergistic interaction between HST-5 and PHS, with IC50 values reduced by 8-fold and 16-fold, respectively. No cytotoxic effects were observed in hGFs cells at the concentration of the synergistic interaction. Conclusions: Therefore, the combination of HST-5 and PHS may enhance the effectiveness of anti-infective agents against S. mutans biofilm, potentially preventing the development of dental caries.
คณะวิทยาศาสตร์
This study aimed to investigate the effectiveness of extracts from moringa seeds, roselle seeds, and tamarind seeds as coagulants to improve water quality in surface water sources. Extracts from these seeds serve as environmentally friendly coagulants and provide alternative options for enhancing surface water quality. The turbidity of surface water sources ranged between 14 and 24 NTU. The coagulation process used the Jar Test method, where the moringa seed, roselle seed, and tamarind seed extracts functioned as both primary coagulants and coagulant aids. In the preparation process, the seeds were finely ground and extracted using a 0.5-M sodium chloride (NaCl) solution. These extracts were then applied as coagulants to reduce turbidity and enhance water quality, with each concentration tested in 300 ml of water. The results indicated that the most effective way to remove turbidity using 2,000 mg/L of moringa seed extract, achieving a turbidity reduction of approximately 73.19% at a cost of 0.0309 baht per 300 ml of water. Followed by Tamarind seed extract, with a concentration of 4,000 mg/L, followed with a turbidity reduction of approximately 56.75% at a cost of 0.0933 baht per 300 ml. Lastly, roselle seed extract at 6,000 mg/L achieved a turbidity reduction of approximately 32.67% at a cost of 0.0567 baht per 300 ml of water.