Chiang Mai University Research Articles

Bunch compression efficiency of the femtosecond electron source at Chiang Mai University

A femtosecond electron source has been developed at the Plasma and Beam Physics Research Facility (PBP), Chiang Mai University (CMU), Thailand. Ultra-short electron bunches can be produced with a bunch compression system consisting of a thermionic cathode RF-gun, an alpha-magnet as a magnetic bunch compressor, and a linear accelerator as a post acceleration section. To obtain effective bunch compression, it is crucial to provide a proper longitudinal phase-space distribution at the gun exit matched to the subsequent beam transport system. Via beam dynamics calculations and experiments, we investigate the bunch compression efficiency for various RF-gun fields. The particle distribution at the RF-gun exit will be tracked numerically through the alpha-magnet and beam transport. Details of the study and results leading to an optimum condition for our system will be presented.

Source of Boron in Curcuma for Burn Symptoms at Leaf Margins

ABSTRACT This study was initiated to investigate the source of boron (B) accumulated in margins of old leaves of Curcuma ‘Chiangmai University Pride’ (‘CMU Pride’). Nutrient elements were analyzed from different parts of the rhizome before potting and from whole rhizomes at harvest, and different leaf locations of young and old leaves during forcing in coarse sand medium. Plants were fertilized with solutions lacking B during the forcing period. Leaf-margin burn symptoms in old leaves of ‘CMU Pride’ could result from the combination of high levels of B and low total N levels. High levels of manganese (Mn) may not be involved in leaf margin-burn symptoms. Boron accumulated in the outer region of the old leaves could result from following evaporation of gutatted water droplets containing dissolved B. High levels of B in the edge of the old leaves may not be transported from the rhizomes.

Low-energy ion beam modification of horticultural plants for induction of mutation

Low-energy ion beam biotechnology, as a newly established and developed highly interdisciplinary technology, has been vigorously applied to modification of horticultural plants for induction of mutations at Chiang Mai University (CMU). Chiang Mai is the horticultural center of Thailand with a magnificent variety of floral resources thanks to its peculiarly favorable environment and climate. Ion beam bombardment induced mutations of flowers have further exploited the horticultural potential. This paper reports recent progress in research and applications of ion beam biotechnology for floral mutation at CMU. Ions at low energies of several tens of keV were implanted into flower seeds, buds and receptacles of various species in vacuum to fluences of an order of 10 16 ions/cm 2 using self-developed special techniques for the living organism survival. A broad spectrum of mutants has been obtained including changes in phenotypes such as the flower color, color intensity, flower shape, and petal shape and size. DNA-fingerprint analysis revealed changes at the DNA level. Physical mechanisms involved in the ion beam induction have been investigated, and however still remained obscure.

Developing Ontology on Commitment of Universities for Research Management

AbstractUniversities’ executives should know expertise and research directions of key researchers in order to formulate strategy and policy for research management efficiently. This management is in term of set up research labs or research clusters depending on the actual potential of researchers in universities. However, it is quite hard to identify who are the key researchers because of two reasons. First, it quite difficult to know clearly what kind of items should be used in criteria for qualifying key researchers. Second, these criteria are dynamic depending on the different of management levels (university, faculty, and department), disciplines (Health Sciences, Science & Technology, and Social Sciences & Humanities), and subjects. This study purposes a framework for developing the ontology on commitment of universities, which enable to identify key researchers and set up research clusters of universities related to the expertise and research directions of key researchers. Chiang Mai University (CMU), Thailand is used as a case study. To this end, first intellectual capitals of CMU are identified through collecting researchers’ information from many sources by using Skandia model, intellectual capital model used for identifying, measuring, and managing intellectual capital easily and clearly, as a frame. Second, key researchers of Chiang Mai University are identified through developing and reasoning the ontology on commitment of Chiang Mai University. Subsequently, research clusters are set up through card sorting technique and analyzing that ontology.

In-Situ atomic force microscopic observation of ion beam bombarded plant cell envelopes

A program in ion beam bioengineering has been established at Chiang Mai University (CMU), Thailand, and ion beam induced transfer of plasmid DNA molecules into bacterial cells (Escherichia coli) has been demonstrated. However, a good understanding of the fundamental physical processes involved is lacking. In parallel work, onion skin cells have been bombarded with Ar+ ions at energy 25keV and fluence1–2×1015ions/cm2, revealing the formation of microcrater-like structures on the cell wall that could serve as channels for the transfer of large macromolecules into the cell interior. An in-situ atomic force microscope (AFM) system has been designed and installed in the CMU bio-implantation facility as a tool for the observation of these microcraters during ion beam bombardment. Here we describe some of the features of the in-situ AFM and outline some of the related work.

Physical check‐up and blood data analysis in the Thai elderly of Chaingmai Province, Thailand

Introduction: Chiangmai is one of the provinces in Northern Thailand. The Aging population has increased rapidly since family planning commenced in 1972. For the surveillance of aging, we started a health investigation of the elderly over 60 years of age in the suburban area of Chiangmai since 1997 with the Nippon Medical School Team.Materials and Method: Medical examination was carried out for the elderly (male = 34, female = 73) at Department of Family Medicine, Chiangmai University, Chiangmai Thailand in August 2002. Chula Mental Test (CMT) was used for cognitive function and Geriatric Depression Scale was used for evaluation of depressive condition.Results: The major health problems of this group of elderly in Chiangmai Province were visual acuity abnormality (98.1%), anemia (66.4%), hypertension (37.4%), dental caries (29%), bone and joint disease (23.4%), cardiovascular disease (11.2%), gingivitis (11.2%), diabetes mellitus (9.3%), digestive system disease (8.4%), and presbycrusis (8.4%). The prevalence of cognitive impairment and depression were 0.9 and 2.8%, respectively. The prevalence of high cholesterol, triglyceride, and LDL cholesterol were 43.9, 29.0, and 15.9%, respectively. The prevalence of high BUN, creatinine, and uric acid were 17.8, 11.2, and 29.9%, respectively. The prevalence of high GOT, GPT, gamma GT, ZTT, and TTT were 4.7, 1.9, 53.3, 35.5, and 21.5%, respectively. The prevalence of low hemoglobin was 66.4%.Conclusion: There was a high prevalence of anemia and hyperlipidemia in this group of elderly in Chiangmai Province. The analysis of background factors and further investigation should be carried out continuously.

Decline of oropharyngeal cancer in Chiangmai province, Thailand, between 1988 and 1999

A decline of oropharyngeal cancer has already been predicted for Thailand since the early 1960s. To substantiate these predictions it was the purpose of this study to examine trends in the incidence of oropharyngeal cancer in the province of Chiangmai, (1988–1999). Data on cancer incidence were extracted from the annual reports of the Cancer Registry, Cancer Unit, Faculty of Medicine, Chiangmai University, Thailand (1992–1999) and an IARC report on cancer in Thailand (1988–1991). The age-standardized annual incidence per 100,000 of oral cancer in males dropped from 3.6 (1988–1991) to 1.2 in 1999 ( P for trend 0.0002) and in females from 2.6 (1988–1991) to 1.1 in 1999 ( P for trend 0.007). Similar trends in males and females for cancer of the tongue, oropharynx and hypopharynx were seen. The age-standardized annual incidence for cancer of the lip, salivary gland and nasopharyngeal carcinoma remained unchanged. Changes of traditional oral habits such as betel quid chewing and smoking of traditional cigars seem to have resulted in a marked decrease of oral cancer in both men and women in the recent past.

Screening of HIV-1 proviral DNA using simple protocol polymerase chain reaction in Thai blood donors

Kunakorn, M; Wichukchinda, N; Raksakait, K; Petchclai, B; Jutavijittum, P*; Mandee, Y*; Kamthon, N*; Kurimura, T† Author Information

Intermittent Aeration for Nitrogen Removal in Small Aerated Lagoon

Intermittent aeration has been proved to be an efficient method in nitrogen removal in many biological treatment processes. Aerated lagoon has been used as domestic wastewater treatment for a small housing estates in Thailand for quite sometime. The purpose of this study is to determine whether intermittent aeration of aerated lagoon could provide efficient nitrogen removal in domestic wastewater. The experiment was carried out using pilot scale aerated lagoon at Chiangmai University. The result showed that 45% of total nitrogen removal could be achieved by aeration and non-aeration of 12 hours each cycle. The intermittent aeration did not affect organic substances removal of the process. Sludge recycle during non-aeration period may improve total nitrogen removal. The method could be introduced to save energy of small wastewater treatment plant.

Materials Design for First-Year Science Students at Chiangmai University

Materials Design for First-Year Science Students at Chiangmai University

Course Design for First-Year Students in English for Science and Technology at Chiangmai University

Course Design for First-Year Students in English for Science and Technology at Chiangmai University