• 제목/요약/키워드: physical diagnostics

검색결과 90건 처리시간 0.031초

산소 유량별 플라즈마 방출광원 세기에 따른 전자온도 진단과 산화주석박막 특성연구 (Study on Electron Temperature Diagnostic and the ITO Thin Film Characteristics of the Plasma Emission Intensity by the Oxygen Gas Flow)

  • 박혜진;최진우;조태훈;윤명수;권기청
    • 한국표면공학회지
    • /
    • 제49권1호
    • /
    • pp.92-97
    • /
    • 2016
  • The plasma has been used in various industrial fields of semiconductors, displays, transparent electrode and so on. Plasma diagnostics is critical to the uniform process and the product. We use the electron temperature of the various plasma parameters for the diagnosis of plasma. Generally, the range of the electron temperature which is used in a semiconductor process used the range of 1 eV to 10 eV. The difference of electron temperature of 0.5 eV has a influence in plasma process. The electron temperature can be measured by the electrical method and the optical method. Measurement of electron temperature for various gas flow rates was performed in DC-magnetron sputter and Inductively Coupled Plasma. The physical properties of the thin film were also determined by changing electron temperatures. The transmittance was measured using the integrating sphere, and wavelength range was measured at 300 ~ 1100 nm. We obtain the thin film of the mobility, resistivity and carrier concentration using the hall measurement system. As to the electron temperature increase, optical and electrical properties decrease. We determine it was influenced by the oxygen flow ratio and plasma.

Evaluation of Clinical Efficacy and Safety Following Kyungokgo-Gamibang Administration in Dogs with Skin and Joint Diseases

  • Ga-Won Lee;Heyong-Seok Kim;Jong-Won Kim;Yang-Seon Moon;Chang-Su Na
    • 한국임상수의학회지
    • /
    • 제40권2호
    • /
    • pp.113-118
    • /
    • 2023
  • Skin and joint diseases are relatively common in dogs. Nutritional complementation is one of the various management strategies for these disorders. This study evaluated the safety and clinical efficacy of Kyungokgo-gamibang in dogs with skin and joint diseases. Thirty dogs with diseases were included and divided into three groups: control group (n = 15), skin group (n = 10), and joint group (n = 5). The skin and joint groups were fed skin and joint gums composed of Kyungokgo-gamibang extract with standard treatment for four weeks. The control group included dogs with skin diseases who were administered standard skin infection treatment for 4 weeks. The physical and laboratory results showed no remarkable adverse effects of Kyungokgo-gamibang extract after its administration in dogs. Clinical efficacy was evaluated using quality of life scale, and levels of cytokines, including interferon-γ, interleukin (IL)-2, IL-6, IL-8, IL-10, monocyte chemoattractant protein-1, and tumor necrosis factor-α, for 4 weeks in all groups. Dermatologic clinical scales were performed for 4 weeks in the control and skin groups. Both the control and skin groups had significantly decreased dermatologic clinical scales, including pruritus and erythema scales (p < 0.05). Among the cytokine levels, only IL-2 concentration was significantly decreased in the skin group after 4 weeks of administration of the Kyungokgo-gamibang extract (p = 0.032). There was no significant difference between the levels of cytokines on days 0 and 28 in the joint group. The quality of life scale was significantly increased after week 4 compared to week 0 in the skin (p = 0.008) and joint groups (p = 0.041). This study suggests that Kyungokgo-gamibang extract can be applied in managing dogs affected by skin and joint diseases without adverse effects.

청계천 수표교(水標橋)의 경관 향상을 위한 진단학적(診斷學的) 훼손상태 분석 (Analysis on the Damage Status by Diagnostical Methodology for the Improvement Landscape on the Supyo-bridge at Chunggae-stream)

  • 안진성;최아현;김유일
    • 한국전통조경학회지
    • /
    • 제28권3호
    • /
    • pp.105-113
    • /
    • 2010
  • 본 연구는 전통공간에 대한 보존계획에 있어서, 대상물의 가치평가를 위하여 수행되는 훼손상태조사에 대한 연구이다. 특히, 전통공간에 위치해 있는 전통 건조물의 보존에 대한 관심과 흥미를 체계화하고 있는 전문가 집단에서 가치평가의 주된 요소로써 대상물의 훼손상태는 어떠한 과정과 방법에 의해서 분석될 수 있는가? 에 대한 과정과 방법론에 관한 실험적인 연구이다. 이를 위하여 본 연구에서는 문화재 '진단학(Diagnostic)'에 대한 이해를 바탕으로 수표교에 대한 물리적 특성과 대상지 환경여건에 대한 이해를 바탕으로 수행하였다. 한편, 본 연구는 그 특성상 수표교의 훼손상태를 기록하기 위하여 작성되는 훼손상태 분포도는 사진측량 기법을 적용한 실측도면을 활용하였고, 대상물의 훼손상태를 조사하기 위한 '평가지침'은 이탈리아 정부의 건축문화재 관리지침이라 할 수 있는 'Raccomandazioni Normal'을 기준으로 하였다. 이러한 연구접근은 국외 건축문화재의 훼손상태 조사에 사용되는 표준지침의 국내 문화재로의 적용 가능성에 대한 실험적인 차원에서 이루어졌음을 밝혀둔다. 그 결과, 수표교의 각 부분별 훼손상태는 침전물에 의한 훼손과 부식 등이 주를 이루고 있었으며, 부식을 비롯한 9가지의 훼손유형의 경우에는 그 구성성분의 물리 화학적 특성과 분포상태를 고려할 때, 수표교의 안전성과 관련하여 위협적인 요소로는 작용하지 않는 것으로 판단하였다. 반면에, 경관 향상을 위하여 상판마루와 멍에석, 그리고 교각부분에서 관찰되는 'Thermoclastism(열전화)' 현상의 경우, 교각을 중심으로 넓게 분포하고 있음을 감안할 때, 훼손부위의 제거와 함께 표면강화 작업의 조속한 처리가 요구될 것으로 판단하였다.

기후변화 및 환경스트레스 영향평가를 위한 한국형 SPAR(Soil-Plant-Atmosphere-Research) 시스템의 개발 (Development of Korean SPAR(Soil-Plant-Atmosphere-Research) System for Impact Assessment of Climate Changes and Environmental Stress)

  • 상완규;김준환;신평;백재경;이윤호;조정일;서명철
    • 한국농림기상학회지
    • /
    • 제21권3호
    • /
    • pp.187-195
    • /
    • 2019
  • 기후변화에 따른 환경 스트레스 대응 기술과 영농의사결정 플랫폼 개발을 위해서는 환경 조건에 따른 작물의 반응을 이해하기 위한 시스템 개발이 매우 중요하다. 본 연구는 한국형 SPAR 시스템이 다양한 환경 조건에서 작물 생육 반응을 어떻게 정량화하고, 향후 작물 생육 모형 개발에 어떻게 연계될 수 있는지에 대해 방향을 제시하고자 수행되었다. 한국형 SPAR 시스템은 온도, $CO_2$ 농도 등의 기상요소와 양 수분 관리 등 재배요소를 동시에 정밀 조절할 수 있을 뿐 만 아니라 군락수준에서 광합성 및 호흡 등 작물의 생육 반응을 실시간으로 정량화하기에 최적화되어 있다. 본 시스템을 통해 수집된 군락 광합성 정보는 실제 작물의 환경조건에 따른 생육량 변동을 매우 유의하게 반영하여 향후 작물 생육 모형에 실질적으로 적용 가능한 환경-유전 요인간 특이적 반응 함수 개발에 크게 활용될 것으로 기대된다.

배유혈(背兪穴) 안진(按診)에 관(關)한 고찰(考察) (A study on Palpation of the back-shu points)

  • 홍문엽;박원환
    • 동국한의학연구소논문집
    • /
    • 제8권2호
    • /
    • pp.155-173
    • /
    • 2000
  • 한의학의 진단(診斷)에는 망(望) 문(聞) 문(問) 절(切)의 사진법(四診法)과 여러 가지의 변증체계(辨證體系), 즉 기혈진액변증(氣血津液辨證) 장부변증(臟腑辨證), 육경변증(六經辨證), 위기영혈변증(衛氣營血辨證), 삼초변증(三焦辨證), 사상체질변증(四象體質辨證) 등이 응용되어 지고 있으며, 또한 그와 더불어 병상(症狀) 증후감병진단법(證候鑑別診斷法)등이 선택적으로 활용되어 지고 있다. 이러한 광범위(廣範位)한 진단방법(診斷方法)가운데 절진(切診)은 손가락 및 손바닥의 감각(感覺)을 운용(運用)해서 일정부위(一定部位)를 촉지(觸指), 접압(接壓)하는 검사방법(檢査方法)으로써 절맥진(切脈診)과 접진(接診)으로 크게 나눌 수 있다. 이중 안진(按診)이란 손을 사용하여 직접 환부에 촉모(觸摸) 안압(按壓)하여 이상변화를 알아내고 나아가서는 질병(疾病)의 부위(部位)와 성질(性質)과 병정(病情)의 경중(輕重) 등의 내부(內部)의 변화(變化)와 체표(體表)의 반응(反應)을 관찰(觀察)하여 중요(重要)한 변증자료(辨證資料)를 얻는 진단방법(診斷方法)의 한 종류(種類)를 말한다. 또한 접진(接診)에는 안기표(按肌表), 접수족(接手足), 안흉복(按胸腹), 접유혈진법(接兪穴診法)등을 들 수 있다. 배유혈(背兪穴)의 진단법(診斷法)은 경기(經綺)이라는 반응로(反應路)를 통(通)하여 체표(體表)에 발현(發現)되는 압통(壓痛), 자발통(自發痛), 긴장(緊張), 이완(弛緩), 경결(硬結) 및 조색상물(條索狀物) 등의 현상(現象)으로 부터 내부장기(內部臟器)의 병변(病變)을 진단(診斷)하는 방법(方法)이다. 이에 저자(著者)는 접진(接診)의 내용(內容)과 방법(方法)을 연구하면서 십이경맥(十二經脈)의 시동병(始動病) 소생병(所生病)을 알아보고 혈위진단(穴位診斷)의 방법(方法) 및 주의점(注意點)등을 아울러 정리하므로써 다음과 같은 결론(結論)을 얻었다. 1. 유혈(兪穴)은 각(各) 장부(臟腑)의 사기(邪氣)가 주입(注入)하는 곳으로 장병(臟病) 한증(寒症) 허증(虛症)의 의미를 내포한 음성병증(陰性病症) 치료(治療)에 중요(重要)한 곳이다. 2. 유차(兪次)의 촉진(觸診) 즉(卽) 모지(母指)로서 척추극돌기(脊椎棘突起) 좌우측(左右側)을 접압(接壓)하여서 상향(上向)이나 하향(下向)으로 추압지(推壓指)하면 극돌기(棘突起)의 돌(突), 함요(陷凹), 긴장(緊張), 이완(弛緩) 및 압통(壓痛)의 출현부위(出現部位)에 따라 계통별(系統別) 질환(疾患)을 판단(判斷)할 수 있다. 3. 실제(實際) 임상(臨床)에서 환자(患者)의 진단(診斷) 치료(治療)에 있어서 배부접진(背部接診)은 중요(重要)한 진단(診斷)의 한 영역(領域)으로 빠뜨리지 말고 꼭 참고(參考)하여야 할 것으로 사료(思料)된다. 4. 장부질환(臟腑疾患)에 대한 진단방법(診斷方法)의 다양화(多樣化)와 치료영역(治療領域)의 확대(擴大) 및 치료율(治療率)의 상승(上昇)을 위해 배부유혈(背部兪穴)의 정확(正確)한 인식(認識)과 유혈접진(兪穴接診)을 통하여 정확(正確)한 진단(診斷)이 되었으면 한다.

  • PDF

우울 경향과 복모혈(腹募穴), 배유혈(背兪穴)압통과의 관계 비교 연구 (Comparative Study of Relationship between the Depressive Tendency and Tenderness of Alarm Points and Transport Points)

  • 서민정;김송이;박영재;정원모;차수진;이향숙;이혜정;박히준
    • Korean Journal of Acupuncture
    • /
    • 제27권4호
    • /
    • pp.97-109
    • /
    • 2010
  • Objective : To examine whether any correlation between tendency towards depression and tenderness at special acupuncture points exists, thus to explore the potential diagnostic property of acupuncture points. Methods : A total 31 subjects were included in this study. They filled out questionnaires about their mental [Beck Depression Inventory (BDI), Stress Response Inventory (SRI), Profile of Mood States (POMS)] and physical (fatigue due to overexertion, and food accumulation) symptoms. Identical weight around Alarm points (CV17, CV12, ST25, CV5, CV4, and LR13) and transport points (BL14, BL20, BL21, BL22, BL25, and BL27) was given using an algometer and the subjects rated their pain on an 11-point numerical rating scale. Heart rate variability (HRV) was also measured. Results : The subjects were divided into two groups, normal and depressive tendency groups with a cut-off point of nine on BDI. The depressive tendency group reported significantly higher values in SRI, POMS, and questionnaire for fatigue due to overexertion. In the pressure pain measurement, depressive tendency group had more pressure pain at CV12, left side of BL20, BL14, BL22 and both sides of BL21, BL25, BL27, significantly (each p<0.05). The data of HRV did not show significant differences between groups. Conclusions : People with a tendency towards depression may be prone to stress, negative mood, and fatigue due to overexertion. In addition, they may be more likely to develop tenderness at alarm points and transport points compared with healthy people. Further research is needed to confirm this finding.

Optical Diagnostics of Nanopowder Processed in Liquid Plasmas

  • Bratescu, M.A.;Saito, N.;Takai, O.
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.17-18
    • /
    • 2011
  • Plasma in liquid phase has attracted great attention in the last few years by the wide domain of applications in material processing, decomposition of organic and inorganic chemical compounds and sterilization of water. The plasma in liquid is characterized by three main regions which interact each - other during the plasma operation: the liquid phase, which supply the plasma gas phase with various chemical compounds and ions, the plasma in the gas phase at atmospheric pressure and the interface between these two regions. The most complex region, but extremely interesting from the fundamental, chemical and physical processes which occur here, is the boundary between the liquid phase and the plasma gas phase. In our laboratory, plasma in liquid which behaves as a glow discharge type, is generated by using a bipolar pulsed power supply, with variable pulse width, in the range of 0.5~10 ${\mu}s$ and 10 to 30 kHz repetition rate. Plasma in water and other different solutions was characterized by electrical and optical measurements. Strong emissions of OH and H radicals dominate the optical spectra. Generally water with 500 ${\mu}S/cm$ conductivity has a breakdown voltage around 2 kV, depending on the pulse width and the repetition rate of the power supply. The characteristics of the plasma initiated in ultrapure water between pairs of different materials used for electrodes (W and Ta) were investigated by the time-resolved optical emission and the broad-band absorption spectroscopy. The deexcitation processes of the reactive species formed in the water plasma depend on the electrode material, but have been independent on the polarity of the applied voltage pulses. Recently, Coherent anti-Stokes Raman Spectroscopy method was employed to investigate the chemistry in the liquid phase and at the interface between the gas and the liquid phases of the solution plasma system. The use of the solution plasma allows rapid fabrication of the metal nanoparticles without being necessary the addition of different reducing agents, because plasma in the liquid phase provides a reaction field with a highly excited energy radicals. We successfully synthesized gold nanoparticles using a glow discharge in aqueous solution. Nanoparticles with an average size of less than 10 nm were obtained using chlorauric acid solutions as the metal source. Carbon/Pt hybrid nanostructures have been obtained by treating carbon balls, synthesized in a CVD chamber, with hexachloro- platinum acid in a solution plasma system. The solution plasma was successfully used to remove the template remained after the mesoporous silica synthesis. Surface functionalization of the carbon structures and the silica surface with different chemical groups and nanoparticles, was also performed by processing these materials in the liquid plasma.

  • PDF

터보프롭엔진(PT6A-62)의 성능저하 진단을 위한 최적 계측 변수 선정에 관한 연구 (A Study on Optimal Parameter Selection for Health Monitoring of Turboprop Engine (PT6A-62))

  • 공창덕;기자영;장현수;오성환
    • 한국추진공학회지
    • /
    • 제4권4호
    • /
    • pp.87-97
    • /
    • 2000
  • 국내에서 최초로 개발된 기본훈련기 KT-1의 추진기관인 터보프롭 엔진(PT6A-62)을 위한 정상상태 성능모사 덴 진단 프로그램을 개발하였다. 개발된 정상상태 성능해석 프로그램의 검증을 위해 해석 결과를 엔진 제작사에서 제공한 성능 데이터 및 가스터빈 엔진의 성능 모사 프로그램으로 잘 알려진 GASTURB와 비교하였다. 개발된 정상상태 성능해석 프로그램의 검증을 위해 해석 결과를 엔진 제작사에서 제공한 성능 데이터 및 가스터빈 엔진의 성능 모사 프로그램으로 잘 알려진 GASTURB와 비교하였다. 개발된 프로그램의 유용성을 검증하기 위해 다양한 고도, 비행마하수, 부분부하에서의 성능을 해석하였다. GPA(Gas Pess Analysis) 방법은 엔진의 성능 저하를 구성품 효율의 저하와 공기유량의 변화량으로 나타내는 방법이다. 오염, 부식, 침식과 같은 물리적 손상을 탐지하기 위한 최적의 계측변수 선정을 위해 GPA 방법은 유용하다. 본 연구에서는 최적의 계측변수를 선정하기 위해 2가지 방법을 이용하였다 하나는 독립변수의 수를 다르게 하여 계측기 수가 진단에 미치는 영향을 알아보았으며 다음 종속변수의 종류가 미치는 영향을 살펴보았다. 해석 결과에 따르면 압축기 입구 온도 및 압력, 압축기 터빈 입구 온도 및 압력, 동력 터빈 입구의 온도 및 압력과 축마력, 연료유량 등을 측정하여 진단에 이용하는 것이 가장 오차가 적었다.

  • PDF

운영연구(OR)의 도서관응용 -그 몇가지 잠재적응용분야에 대하여- (The Application of Operations Research to Librarianship : Some Research Directions)

  • 최성진
    • 한국문헌정보학회지
    • /
    • 제4권
    • /
    • pp.43-71
    • /
    • 1975
  • Operations research has developed rapidly since its origins in World War II. Practitioners of O. R. have contributed to almost every aspect of government and business. More recently, a number of operations researchers have turned their attention to library and information systems, and the author believes that significant research has resulted. It is the purpose of this essay to introduce the library audience to some of these accomplishments, to present some of the author's hypotheses on the subject of library management to which he belives O. R. has great potential, and to suggest some future research directions. Some problem areas in librianship where O. R. may play a part have been discussed and are summarized below. (1) Library location. It is usually necessary to make balance between accessibility and cost In location problems. Many mathematical methods are available for identifying the optimal locations once the balance between these two criteria has been decided. The major difficulties lie in relating cost to size and in taking future change into account when discriminating possible solutions. (2) Planning new facilities. Standard approaches to using mathematical models for simple investment decisions are well established. If the problem is one of choosing the most economical way of achieving a certain objective, one may compare th althenatives by using one of the discounted cash flow techniques. In other situations it may be necessary to use of cost-benefit approach. (3) Allocating library resources. In order to allocate the resources to best advantage the librarian needs to know how the effectiveness of the services he offers depends on the way he puts his resources. The O. R. approach to the problems is to construct a model representing effectiveness as a mathematical function of levels of different inputs(e.g., numbers of people in different jobs, acquisitions of different types, physical resources). (4) Long term planning. Resource allocation problems are generally concerned with up to one and a half years ahead. The longer term certainly offers both greater freedom of action and greater uncertainty. Thus it is difficult to generalize about long term planning problems. In other fields, however, O. R. has made a significant contribution to long range planning and it is likely to have one to make in librarianship as well. (5) Public relations. It is generally accepted that actual and potential users are too ignorant both of the range of library services provided and of how to make use of them. How should services be brought to the attention of potential users? The answer seems to lie in obtaining empirical evidence by controlled experiments in which a group of libraries participated. (6) Acquisition policy. In comparing alternative policies for acquisition of materials one needs to know the implications of each service which depends on the stock. Second is the relative importance to be ascribed to each service for each class of user. By reducing the level of the first, formal models will allow the librarian to concentrate his attention upon the value judgements which will be necessary for the second. (7) Loan policy. The approach to choosing between loan policies is much the same as the previous approach. (8) Manpower planning. For large library systems one should consider constructing models which will permit the skills necessary in the future with predictions of the skills that will be available, so as to allow informed decisions. (9) Management information system for libraries. A great deal of data can be available in libraries as a by-product of all recording activities. It is particularly tempting when procedures are computerized to make summary statistics available as a management information system. The values of information to particular decisions that may have to be taken future is best assessed in terms of a model of the relevant problem. (10) Management gaming. One of the most common uses of a management game is as a means of developing staff's to take decisions. The value of such exercises depends upon the validity of the computerized model. If the model were sufficiently simple to take the form of a mathematical equation, decision-makers would probably able to learn adequately from a graph. More complex situations require simulation models. (11) Diagnostics tools. Libraries are sufficiently complex systems that it would be useful to have available simple means of telling whether performance could be regarded as satisfactory which, if it could not, would also provide pointers to what was wrong. (12) Data banks. It would appear to be worth considering establishing a bank for certain types of data. It certain items on questionnaires were to take a standard form, a greater pool of data would de available for various analysis. (13) Effectiveness measures. The meaning of a library performance measure is not readily interpreted. Each measure must itself be assessed in relation to the corresponding measures for earlier periods of time and a standard measure that may be a corresponding measure in another library, the 'norm', the 'best practice', or user expectations.

  • PDF

Positron Annihilation Spectroscopy of Active Galactic Nuclei

  • Doikov, Dmytry N.;Yushchenko, Alexander V.;Jeong, Yeuncheol
    • Journal of Astronomy and Space Sciences
    • /
    • 제36권1호
    • /
    • pp.21-33
    • /
    • 2019
  • This paper focuses on the interpretation of radiation fluxes from active galactic nuclei. The advantage of positron annihilation spectroscopy over other methods of spectral diagnostics of active galactic nuclei (therefore AGN) is demonstrated. A relationship between regular and random components in both bolometric and spectral composition of fluxes of quanta and particles generated in AGN is found. We consider their diffuse component separately and also detect radiative feedback after the passage of high-velocity cosmic rays and hard quanta through gas-and-dust aggregates surrounding massive black holes in AGN. The motion of relativistic positrons and electrons in such complex systems produces secondary radiation throughout the whole investigated region of active galactic nuclei in form of cylinder with radius R= 400-1000 pc and height H=200-400 pc, thus causing their visible luminescence across all spectral bands. We obtain radiation and electron energy distribution functions depending on the spatial distribution of the investigated bulk of matter in AGN. Radiation luminescence of the non-central part of AGN is a response to the effects of particles and quanta falling from its center created by atoms, molecules and dust of its diffuse component. The cross-sections for the single-photon annihilation of positrons of different energies with atoms in these active galactic nuclei are determined. For the first time we use the data on the change in chemical composition due to spallation reactions induced by high-energy particles. We establish or define more accurately how the energies of the incident positron, emitted ${\gamma}-quantum$ and recoiling nucleus correlate with the atomic number and weight of the target nucleus. For light elements, we provide detailed tables of all indicated parameters. A new criterion is proposed, based on the use of the ratio of the fluxes of ${\gamma}-quanta$ formed in one- and two-photon annihilation of positrons in a diffuse medium. It is concluded that, as is the case in young supernova remnants, the two-photon annihilation tends to occur in solid-state grains as a result of active loss of kinetic energy of positrons due to ionisation down to thermal energy of free electrons. The single-photon annihilation of positrons manifests itself in the gas component of active galactic nuclei. Such annihilation occurs as interaction between positrons and K-shell electrons; hence, it is suitable for identification of the chemical state of substances comprising the gas component of the investigated media. Specific physical media producing high fluxes of positrons are discussed; it allowed a significant reduction in the number of reaction channels generating positrons. We estimate the brightness distribution in the ${\gamma}-ray$ spectra of the gas-and-dust media through which positron fluxes travel with the energy range similar to that recorded by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) research module. Based on the results of our calculations, we analyse the reasons for such a high power of positrons to penetrate through gas-and-dust aggregates. The energy loss of positrons by ionisation is compared to the production of secondary positrons by high-energy cosmic rays in order to determine the depth of their penetration into gas-and-dust aggregations clustered in active galactic nuclei. The relationship between the energy of ${\gamma}-quanta$ emitted upon the single-photon annihilation and the energy of incident electrons is established. The obtained cross sections for positron interactions with bound electrons of the diffuse component of the non-central, peripheral AGN regions allowed us to obtain new spectroscopic characteristics of the atoms involved in single-photon annihilation.